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High-frequency trading and dark liquidity
Since August 2010, the Australian Securities and Investments Commission
(ASIC) has had responsibility for the supervision of real-time equities trading
on Australia's domestic licensed markets (the Australian Securities Exchange (ASX)
and Chi-X) in accordance with the Corporations Act 2001 and ASIC market
integrity rules. Part of ASIC's remit is to examine market changes and
determine the adequacy of the existing regulatory regime. ASIC's key objective
is to promote 'investor confidence through fair and efficient markets'.
Australia's financial markets are undergoing significant structural and
Two areas of evolution, both within Australia and globally, involve
high-frequency trading and dark liquidity (also referred to as dark venues or dark
pools). High-frequency trading and dark liquidity were raised by ASIC and the
ASX at the December 2012 hearings and have been the subject of media attention
and public concern.
In mid-2012, ASIC established two taskforces to inquire into and report
on high-frequency trading and dark liquidity. These reports were released on
18 March 2013, three days after the committee's public hearing. As a
consequence, ASIC provided little evidence relating to dark liquidity and high-frequency
trading at the public hearing and this chapter therefore relies mainly on the
For ease of explanation, the attributes of dark liquidity and high-frequency
trading are dealt with separately in the following sections. However, dark
liquidity and high-frequency trading interact in their influence on investor
and are therefore considered together in the section on new Market Integrity
Rules. In its concluding comments, the committee draws attention to these
interactions and their implications for regulatory proposals.
What is dark liquidity?
Dark liquidity refers to client orders that are matched away from the
'lit' exchange market. There is no pre-trade transparency with dark trading because
the orders are not displayed on order books and are 'not known to the rest of
the market before the orders are matched as executed trades'.
Dark trades in Australia can occur on both the public exchange markets,
such as the ASX’s Centre Point and hidden orders on Chi-X’s order book, as well
as at unlicensed venues away from the markets.
In a dark trade, a market participant
'may choose to fill the order from its own inventory (known as
internalisation), or may choose to "cross" it with other client
orders' rather than send the order to the lit market.
ASIC ascribes the development of dark liquidity to technological change:
Advances in technology have made it easier to trade away from
exchange markets and have facilitated a proliferation of dark trading venues
known as ‘crossing systems’ and ‘dark pools’.
The size of dark trading in
ASIC found over 20 dark venues in Australia, accounting for around 7 per
cent of the total equity share.
The amount of trading in dark pools has remained relatively unchanged at 25–30
per cent of total trading. In recent years, however, there has been a
significant change in the type of trades that are occurring in dark pools, with
'fewer large block trades, and many more small trades'.
Private incentives to trade in the
There are several incentives for clients to trade in the dark, including
the ability to conceal trading intentions from other traders, and the potential
to get 'better prices or faster execution'.
Market participants are also able to save on the fees associated with
the exchange market and can also choose 'which client flow to interact with'.
However, a key finding from ASIC's investigation is evidence that some clients
perceive dark venues to be safer than lit markets because they allow clients to
avoid interaction with algorithmic and high-frequency trading on the lit
exchange markets. ASIC believes that fundamental long-term investors have moved
away from lit markets because they view high-frequency trading as 'predatory,
unfair, and a barrier to efficient long-term investment'.
Public benefits of dark liquidity
Treasury notes two key public benefits that accrue from the presence of
dark liquidity. Firstly, dark pools benefit the market by creating competition
through the development of rival markets. Secondly, the ability to execute very
large or block trades in dark venues has the advantage of avoiding a market
impact on the lit exchange.
Concerns about dark liquidity
Concerns about dark liquidity include regulatory inconsistency between
lit markets and dark venues, detrimental impacts on efficient price formation
in lit markets, conflicts of interest between market participants and clients,
and a loss of investor confidence.
Treasury has expressed concern that the regulatory landscape is
inconsistent between markets that are effectively competitors, for example
public exchanges and dark pools', because:
- dark pools are not formally licensed, with operators subject to
the market integrity rules only through the fact that they are all market
participants in public exchanges and hold an Australian Financial Services
Licence (AFSL); and
- markets that are unlicensed face fewer compliance requirements,
and are also not directly included in the cost recovery regime for market
surveillance. This creates a competitive advantage for those outside of the
market licensing regime, and also reduces the effectiveness of market
The lack of pre-trade transparency in dark pools has led to concerns
that the growth of dark liquidity will impede price discovery and optimal price
formation in the lit exchange markets.
Furthermore, a shift in liquidity from lit markets to dark venues will reduce
the number of lit orders, potentially widening bid-offer spreads and leading to
worse prices for all involved.
Australian research by Carole Comerton-Forde and Talis Putnins concludes
that dark liquidity in excess of 10 per cent of total trading (excluding large
block trades) harms price formation. By contrast, their study confirmed current
understandings that having up to 15 per cent by dollar volume of block trades
executed away from the lit markets could 'be beneficial to aggregate price
Further issues around dark liquidity relates to fairness. Dark venues
are not regulated like the public markets, and there are concerns that dark
venues '"free ride" on the pricing and information set on exchange
The ability of dark venues to fill orders internally or cross them with
other client orders has triggered concerns about the fairness of crossing
systems, because the dark venue has prior knowledge of the trading intentions
of a client.
A conflict of interest arises when a dark venue may act as both executor of,
and active participant in, a trade. Principal trading by a crossing system
operator may undermine investor confidence in trade execution and market
A further concern is that under existing rules on dark liquidity,
investors in lit markets are exposed to a higher level of risk from trades that
occur in dark pools because:
... dark orders can be filled before orders at the same price
that have been waiting in the queue on a lit exchange market. This results in
investors that display liquidity waiting longer for their orders to be
executed, which exposes their orders to greater risk of non-execution and
adverse price movements (i.e. adverse selection).
What is high-frequency trading
High-frequency trading is a subset of algorithmic trading that uses
sophisticated technological tools with a resulting impact on the execution of
Advances in technology have also fundamentally changed the
way orders are generated and executed by all users of the market. Rather than
orders being generated and executed manually, most orders are now generated and
executed by computer programs running decision and execution algorithms.
ASIC notes that '[a]lgorithmic programs are now used widely by market
participants and buy-side clients to execute trades on and off market' and that
'at least 99.6% of all trading messages submitted to market...were sourced from
an automated order processing program'.
ASIC distinguishes high-frequency trading from algorithmic trading and
notes that high-frequency trading exhibits the following characteristics:
- high daily portfolio turnover;
- high order-to-trade ratios where large numbers of trades are
cancelled in comparison to trades executed;
flat or near flat positions at the end of the trading day;
- holding positions for as little as seconds or fractions of a
- reliance on the ability to be faster than competitors and to take
advantage of services such as direct electronic access and co-location.
ASIC found that the flat positions at the end of a trading day are the
element that most distinguishes high-frequency trading from other algorithmic
The attribute that most clearly characterises high-frequency
trading and differentiates it from other trading is the percentage of turnover
bought and then sold, or sold and then bought, within each trading day.
High-frequency traders tend to close out a high proportion of trading intraday,
so their overnight positions are relatively small. This metric distinguishes
high-frequency trading from the more widespread execution algorithms which
trade in only one direction during a day.
The size and location of
high-frequency trading in Australia
ASIC analysed all trading on Australian equity markets 'over the
nine-month period from January to September 2012'.
It found 550 high-frequency traders,
but pointed out that high-frequency trading in Australia is dominated by a
small group of trading entities that comprise 'specialised trading desks within
major investment banks, proprietary trading firms and some hedge funds'.
The 10 largest high-frequency trading entities account for approximately 60 per
cent of all high-frequency trading turnover, while the 20 largest high-frequency
trading entities account for approximately 80 per cent of all high-frequency
trading turnover. High-frequency trading accounts for 27 per cent of total
turnover on the ASX 200, and 22 per cent of total equity market turnover.
In total, high-frequency trading accounted for 32 per cent of total
trades and 46 per cent of total orders, 'consistent with the finding that
high-frequency traders generally have higher order-to-trade ratios'.
ASIC found that although 95 per cent of high-frequency trades occur in
the lit market, high-frequency traders are also active in dark venues,
including crossing systems. The 5 per cent of high-frequency trades conducted
in the dark is still significantly less than the 14 per cent of trades
conducted in the dark by other traders.
Concerns about high-frequency
High order-to-trade ratios
ASIC found that high-frequency trading shares some of the same
attributes as other algorithmic trading, including high order-to-trade ratios
and short resting times.
High order-to-trade ratios generate large numbers of messages or 'noise' and
mean that market participants and operators, as well as ASIC, need to store and
manage larger amounts of data. This can increase trading costs.
However, order-to-trade ratios on the Australian market 'fell
substantially in February 2012 and trended downwards over the rest of the
period analysed'. ASIC notes that this fall coincided 'with the implementation
of Treasury’s cost recovery program which, for market participants, commenced
on 1 January 2012'.
ASIC also notes that the limited data that is available appears to indicate
that order-to-trade ratios in Australia are low compared to some overseas
jurisdictions, such as Canada, the United States, and Europe.
Holding times and fleeting orders
One of the concerns about high-frequency trading has been that
sub-second trading allows cross-market arbitrage between lit exchanges.
However, ASIC found that holding times were longer than previously anticipated,
with the average trading time being 42 minutes. The breakdown of holding times
is as follows:
0.1 per cent of high-frequency traders held positions for less
than one second;
- 1.2 per cent were held for an average of two minutes or less;
- 18 per cent were held for less than 10 minutes; and
51 per cent for less than 30 minutes.
ASIC also found that while small fleeting orders 'contribute to market
noise' and 'do not add to market liquidity and are potentially misleading when
posted at new price levels', high-frequency trading was not responsible for the
vast majority of small fleeting orders. Instead, 76 per cent of these orders
are likely to arise from the algorithms used by other market participants.
High-frequency operators have been criticised for having an unfair
advantage, particularly where a trader's processing system is co-located with a
market operator's execution engine. Co-location benefits traders whose trading
and business strategies rely on speed, because of the reduced delay or latency
in 'transmitting and receiving trading messages'.
However, ASIC notes that the 'need for low latency market access is not crucial
to all investors'.
Furthermore, ASIC did not find co-location unfair and noted that both
algorithmic traders and high-frequency traders have access to, and use,
We do not regard the fact that market participants can
co-locate to obtain a speed advantage as inherently unfair. Speed of access to
the market has always been contestable, from the days of physical proximity on
the floor, when an open outcry system operated. We recognise that not all
market operators choose to operate at the co-location site with the lowest
latency, but for those who do, our concern is to ensure that the facilities for
doing so are made available to them on a fair basis and on transparent terms.
Our assessment is that access to these services is fair.
Market operators offer economically reasonable and transparent pricing,
inclusive of ongoing fee costs, that is publicly available and access to these
services is available on a non-discriminatory basis. Network connections within
co-location facilities are precisely measured, and all participants within the
facility receive their data feed with exactly the same latency as any other
participant running the same options.
A number of concerns have been raised concerning predatory trading
strategies that depend on technology and speed for their execution. Concerned
investors have raised the following with ASIC:
- layering: the creation of large numbers of orders, often at
various price points, to create a false impression of demand or supply. These
orders are then deleted, or moved, as they move closer to trading;
- quote stuffing: a strategy to impede the processing of
markets, or participant processes, by overloading an order book with trading
- latency arbitrage: a strategy that detects the submission
of individual orders and steps ahead of it by using superior speed;
- liquidity detection: a strategy that determines the
direction of fundamental investor demand and ‘front runs’ its execution to
create higher execution costs for market users; and
- momentum ignition: a strategy that drives prices
artificially over range.
Further concerns about high-frequency trading relate to the perceived
lack of value created by high-frequency trading, and the potential detrimental
impact on long-term investment and capital allocation.
Predatory trading strategies constitute market abuse and ASIC
investigates all suspected instances 'and takes enforcement action if
appropriate'. ASIC found 'no direct relationship between high-frequency trading
and abusive layering', but is investigating one 'instance of potential market
abuse using layering by a high-frequency trader'.
ASIC had 'no concerns at this stage that systemic levels of quote
stuffing would compromise the current processing capacity of the Australian
ASIC also found that concerns about arbitrage were misplaced because:
... market operators are required to provide market data on a
fair, transparent and non-discriminatory basis. No trader is capable of
detecting any submitted market message before acceptance by that operator.
Furthermore, ASIC observed that high-frequency traders and
other algorithmic traders operate at very high speeds and that other market
participants need to account for this when using their own 'smart order
routers' which may be considerably slower.
Investors are concerned liquidity detection and the possibility that 'high-frequency
trading is interposing ‘toxic’ liquidity between natural buyers and sellers, and
thereby increasing execution costs for fundamental investors'. ASIC found
instances of 'potentially predatory activity' and in response, the traders
... in some cases responded positively to our intervention by
modifying their algorithms, ceasing all trading in the market and in other
cases they have been referred to Enforcement for investigation.
As a result of the 'behavioural change by traders', market
quality has improved markedly with a 40 per cent reduction in pre-open market
In response to concerns about momentum ignition, ASIC found 'no evidence
of strategies being employed to create or exacerbate price moves and
accordingly to open or unwind positions at a favourable price'.
Over the last year, ASIC did identify and take action against market
abuse perpetrated by some high-frequency traders:
ASIC has identified instances of abusive and dysfunctional
trading by some high-frequency traders. This has primarily involved foreign
high-frequency traders and large-scale wash trading, with this conduct
presently the subject of enforcement action.
Market making and maker-taker
ASIC is also keeping a watch on two activities that are associated with,
though not exclusive to, high-frequency trading: market making and maker-taker
pricing and proprietary trading firms accessing markets as participants.
Market makers 'provide liquidity when it is generally weak or absent',
and also 'manage short-term imbalances in supply and demand'. Market makers are
'formally registered' in many overseas exchange markets where they are 'subject
to specific obligations' and entitled to 'specific benefits'. ASIC notes that
these arrangements have not been part of the Australian equity market, but that
electronic liquidity providers are becoming 'more prevalent' as a result of the
'increasingly low-latency trading environment in Australia and the introduction
of competition in exchange markets'.
Maker-taker pricing is used to attract liquidity by exchange market
operators. ASIC notes that this phenomenon is now appearing in Australia. ASIC
remarks that the evidence about the extent of the impact of maker-taker pricing
is mixed, but notes that the payment of a rebate to a price maker by an
exchange market operator can 'create inefficiencies in pricing' and 'distort
trading behaviour'. Neither Chi-X nor the ASX maker-taker models pay a rebate
to price makers. ASIC notes that it 'would be concerned if pricing incentives
influence behaviour in a way that is not in the best interests of clients and
wider market integrity'.
Proprietary trading firms accessing
markets as participants
There has been an increase in 'the number of proprietary trading firms entering
Australian markets' relative to 'firms executing trades for clients'. Many of
these proprietary trading firms employ algorithmic and high-frequency trading
strategies which carry risks that include:
... large potential market exposures via orders which they may
not only not be able to fund, but which may cause disorder where the market is
volatile, or where an attempt is made to close out an unintended position.
ASIC intends to make sure clearing firms have effective systems in place
to deal with the potential risks including:
... appropriate and effective management of clearing and
market-related risks throughout the clearing and settlement system. This must
include real-time monitoring and control by clearing participants of pre and
post-trade exposure of their clients, in a highly automated environment where
algorithms can quickly create disorderly market events.
New Market Integrity Rules for dark liquidity and automated trading
ASIC remarks upon 'the inherent tension' between the 'short-term private
advantages' that accrue to those trading in the dark and the 'long-term public
good of contributing to the price formation process' which promotes investor
confidence and the efficient capital allocation to listed companies.
The original rules on dark liquidity were designed to protect block
trades because it was deemed beneficial to execute block trades away from the
lit market. Given the concerns about the growth in small trades being conducted
in dark pools, the recent shift that has occurred in dark liquidity operations
with fewer block trades and a greater amount of smaller trades has regulatory
In response to concerns about dark liquidity and high-frequency trading,
the government has introduced new Market Integrity Rules relating to dark
liquidity and automated trading that are due to take effect between May 2013
and May 2014. These include:
- a price improvement requirement for dark trades, to encourage
more trading to occur on lit exchange markets and support the price formation
process (May 2013);
- enhancements to the market operator controls for extreme price
movements, including automated trading pauses (May 2013 and 2014);
- enhancements to market participant filters and controls for automated
trading, including a 'kill switch' to immediately shut down problematic
algorithms (May 2014); and
- enhancements to the data ASIC receives to improve our market
surveillance (March 2014).
ASIC expects that the new meaningful price improvement rules will
'encourage more trading to occur on lit exchange markets' and will also 'protect
lit orders from being traded ahead of by dark trades at the same price'.
ASIC expects that the automated trading pauses and 'kill switches' will
reduce the potential for algorithms to exacerbate market volatility and cause
liquidity to disappear.
Further regulatory proposals
Treasury consultation paper
As well as the new Market Integrity Rules, further regulatory proposals
have arisen from both a Treasury consultation paper and the investigation into
dark liquidity and high-frequency trading by the two internal ASIC taskforces.
Treasury released a consultation paper in November 2012, Australia's
financial market licensing regime: Addressing market evolution. Amongst
other proposals, feedback was sought on legislative changes to regulate dark
pools, crossing systems and high-frequency trading.
ASIC supports the first option put forward by Treasury to 'create
flexibility in the Corporations Act, augmented by ASIC rules and guidance' in
order to 'create a number of market categories with tailored licensing
ASIC supports the principle of flexible licensing and
supports proposals in the Treasury consultation paper for the introduction of
specific Market Integrity Rules relating to some dark pool activities.
ASIC also supports the Treasury proposal to make the relevant traders
directly subject to Market Integrity Rules:
We support the position that traders that design and use
algorithms should be subject directly to Market Integrity Rules.
ASIC consultation papers
Following the release of its report into dark liquidity and high-frequency
trading, ASIC released a consultation paper in March 2013 on dark liquidity and
high-frequency trading. Proposals to amend the Market Integrity Rules relating
to dark liquidity included:
- a minimum size threshold for dark orders;
transparency, disclosure, fairness, monitoring, record keeping,
and system controls requirements for crossing operators;
- reducing tick sizes for tick constrained securities;
- enhanced conflict of interest obligations for market participants;
- indications of interest relating to the possible leakage of a
client's trading intentions.
A minimum size threshold for dark orders is proposed as a 'safety net
against future degradation of price formation if dark liquidity grows despite
the introduction of meaningful price improvement in May 2013'. ASIC notes that
the introduction of a threshold 'is likely to eliminate 90–99% of dark trading
below block size, which accounts for 20–40% of dark trading value below block
ASIC proposals to address high-frequency trading relate to excessive
messaging and market noise (in particular, small and fleeting orders and
order-to-trade ratios) and manipulative trading.
Despite the significant reduction in message volume since the
introduction of cost-recovery in January 2012, ASIC has 'concluded that small
and fleeting orders are impacting market integrity and efficiency and investor
confidence' and that therefore 'it is appropriate to require these orders to
rest for a minimum amount of time in our markets'.
ASIC does not see order-to-trade ratios as a market-wide problem, but is
concerned to ensure that it does not become a major issue in the future.
Accordingly, ASIC proposes to update its guidelines for market participants to
include the appropriate consideration of the impact of order-to-trade ratios.
Various forms of manipulative and predatory trading are already covered
in the Corporations Act as well as the rules that apply to the ASX and Chi-X.
However, ASIC also proposes 'to enhance the current Market Integrity Rules to
address manipulative trading practices that may be affected through trading
At the 15 March hearing, Mr Medcraft indicated that having conducted its
investigation, ASIC viewed algorithmic and high-frequency trading as the 'new
normal' and that ASIC would look at managing it:
In relation to algorithmic trading, of which high frequency
is a subset, the general theme is that it is probably the new normal and we
need to see how we manage it.
The committee is concerned that activity outside the lit market may
impede the discovery of clear price signals on the lit market and looks forward
to hearing from ASIC about the impact that the new price improvement rules have
had on dark trading volumes.
The committee agrees with ASIC's approach to addressing small volume
dark trades with the meaningful price improvement mechanism, particularly in
light of research that finds a detrimental impact on optimal price formation
once the volume of dark trades (excluding block trades) exceeds 10 per cent. The
committee notes the Treasury proposals to introduce regulatory consistency in
terms of licensing and compliance between lit markets and dark venues. However,
the committee also notes the view expressed by Treasury that dark venues
provide a public benefit by enhancing competition in the Australian market. The
committee is mindful of retaining a balance between the needs of the lit market
including optimal price formation and the benefits of greater competition. Given
that the meaningful price improvement rule will already be in operation, and
that proposals to apply licensing and compliance requirements to dark venue
operators may be taken up, the committee seeks ASIC's perspective on the need
for a minimum size threshold for dark trades.
The committee is concerned about the level of competition on the lit
exchange markets in Australia, and whether there is any evidence that a lack of
competition is causing investors to seek better deals in dark pools. At the
next oversight hearing in June, the committee will seek comment from ASIC on
The committee is concerned that with the capacity to act as both
executor and active participant in a trade, a dark venue has the ability to
trade against its client. The committee is pleased that ASIC is consulting on
this issue and the committee is keen to know what feedback ASIC has received
about this conflict of interest.
The committee is concerned about the potential detrimental impact of
high-frequency trading on the efficient allocation by the stock market of
capital to firms over the long term. The committee looks forward to questioning
ASIC about its method for looking at high-frequency trading and the conclusions
it has reached in this regard.
The committee notes that ASIC aims to move investors out of dark pools
and into the lit market with the price improvement rule. However, the committee
is concerned that long-term investors are moving out of the lit exchange
markets and into dark pools in order to escape high-frequency trading. The
committee seeks an explanation from ASIC about this apparent contradiction particularly
given that ASIC has indicated that high-frequency trading may be the 'new
The committee is keen to know whether ASIC's conclusion about misplaced
concern over high-frequency trading is a result of the relatively low volume of
high-frequency trading, or is it a broader governance issue where ASIC believes
that effective mechanisms are in place to deal with higher volumes of high-frequency
trading. The committee is also keen to know whether ASIC believes that long
term investors are mistaken in their concerns about high-frequency trading, and
whether ASIC would re-visit the issue of high-frequency trading if there were
further developments in the future.
The committee is mindful that new market integrity rules are due to come
into effect over the next eighteen months. At its next oversight hearing in
June, the committee will question ASIC on how its taskforces will overlap with
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