Applicable in all market conditions - focuses on execution quality
| Strategy Type | Execution Optimisation and Transaction Cost Reduction System |
| Market Outlook | Applicable in all market conditions - focuses on execution quality |
| Risk Profile | Reduces implicit trading costs; improves net returns |
| Reward Profile | Cumulative savings from reduced slippage compound significantly |
| Time Horizon | Per-trade execution; cumulative impact over trading career |
| Capital Requirement | All capital levels benefit; larger sizes benefit more from optimisation |
| Margin Type | N/A - execution methodology, not a position type |
| Best Used When | Every trade - execution quality always matters |
| Asx Applicability | All ASX-listed equities and Exchange-Traded Options (ETOs); applies across the lit limit order book, Centre Point (midpoint dark), and the opening/closing auctions |
| Asx24 Applicability | ASX 24 derivatives - SPI 200 index futures, single stock futures, and agricultural/energy futures (wheat, barley, canola, wool, electricity) |
| Asic Compliance | Fully compliant - standard order-management practices under the ASIC Market Integrity Rules and ASX Operating Rules. Best-execution obligations apply when liquidity is fragmented across ASX and Cboe Australia |
| Venue Structure | Lit equity liquidity is split between ASX and Cboe Australia (formerly Chi-X). SPI 200 and other futures trade on ASX 24. Smart order routing and venue selection are part of execution quality, unlike a single-venue market |
| Retail Instrument Notes | SPI 200 index futures (A$25/pt) and ASX ETOs are the liquid retail derivatives. Single stock futures are listed but thinly traded - most single-name leverage is taken via CFDs. ASX 24 commodity and FX futures are real but largely institutional/agricultural; retail commodity and FX exposure is usually via CFDs or ETFs |
| Trading Sessions | 07:00-09:59 Sydney time - order entry and amendment, no matching (queued in price/time priority) • Opening single-price auction ~09:59:45 (randomised 15s); equities open in staggered alphabetical groups through ~10:09 • 10:00-16:00 - continuous matching in price/time priority (the bulk of the day's volume) • Pre-CSPA 16:00-16:10 (no matching); Closing Single Price Auction ~16:10-16:12; Post-Close lit session 16:11-16:21:30 at the official close price • SPI 200 trades nearly around the clock: day session ~09:50-16:30 and overnight session ~17:10-07:00 Sydney time, tracking US and European markets |
| Liquidity Patterns | 10:00-11:00 and 15:00-16:00; the Closing Single Price Auction (~16:10) is the single deepest liquidity event of the day • 11:00-12:00, 14:00-15:00 • 12:00-14:00 (midday lull) • SPI 200 night session is thinner than the day session but tradable; spreads widen and depth drops outside Sydney hours • SPI 200 expiry (3rd Thursday, noon settlement) and ETO/index-option expiries bring higher volume but wider intraday swings |
| Typical Spreads | 1 point (A$25 per contract) in the front month - very tight • 1-2 cents on BHP, CBA, CSL, NAB, WBC (highly liquid) • 1-5 points depending on moneyness (A$10/point) • 5-20+ cents on illiquid stock options (wide spreads) • several cents to a meaningful % of price (percentage terms very high) |
| Order Types Available | ASX has no unlimited market order - a Market-to-Limit fills against the best available price, then rests any unfilled balance as a limit at that price • Execute only at the specified price or better • Midpoint dark order - matches at the midpoint of the ASX best bid/offer, capturing roughly half the spread; the single most useful native slippage-reduction tool • Stop and stop-limit orders are held at the broker level (ASX has no native stop); when triggered they send a Market-to-Limit or limit order • Undisclosed-volume order showing only a small portion of the total size to the market • Immediate or cancel - fill what is available, cancel the rest (FOK fills entirely or cancels) • Good-till-cancelled / good-till-date persistent orders (subject to broker support) |
No, slippage is rarely the broker's fault. Main causes: 1) Bid-ask spread - a natural market cost, not broker-related. 2) Market impact - your order affects prices. 3) Timing - prices move while you decide/execute. 4) Your order-type choice - aggressive orders cause more slippage. Brokers add explicit costs (brokerage) but slippage is mostly about market mechanics and your execution choices. Better execution practices on your end can dramatically reduce slippage regardless of broker.
Limit orders should be your default, but not the only tool. Use limit orders when the trade is not time-sensitive, you want to control price, or spreads are wide. On the ASX you can also use a Centre Point order to match at the midpoint and save half the spread. Use a Market-to-Limit when the trade is urgent (a fast-moving opportunity), the instrument is very liquid with tight spreads, and waiting would cost more than the spread. A balanced approach: start with a limit slightly inside the spread; if it isn't filling and urgency rises, become more aggressive. Reserve aggressive orders for genuine emergencies.
Let's calculate: assume an average 2 points of slippage on SPI 200. Monthly trades: 50. Per-trade cost: 2 x A$25 = A$50. Monthly cost: 50 x A$50 = A$2,500. Annual cost: A$30,000. If you're making A$300,000/year profit, slippage is 10% of profits. If you're making A$50,000/year, slippage is 60% of profits! The impact is larger for smaller profits. For frequent traders, slippage can absolutely be the difference between profitable and losing trading. It's worth significant effort to reduce.
Several reasons: 1) Queue position - others placed limit orders at that price before you (price/time priority), so they fill first and the price may move before your turn. 2) Partial depth - not enough volume at that price to fill everyone. 3) Price touched briefly - it just touched your level and bounced, with not enough time/volume for your fill. 4) Quote flicker - the displayed price was stale or flickered. Solutions: place limits earlier (queue priority), use slightly more aggressive prices, or accept that some limits won't fill.
The single most impactful change: stop using aggressive orders by default. Switch to limit orders placed at or just inside the current spread - or use a Centre Point order to match at the midpoint. Example: if the SPI 200 bid is 8,700 and the ask is 8,702, place your buy limit at 8,701; you'll often get filled there instead of paying 8,702. This alone can cut slippage by 30-50% with minimal effort. Second simple change: don't trade during the midday lull (12:00-14:00) if you don't have to - spreads are wider and slippage higher. These two changes require almost no skill but have immediate impact.
Compare your order to visible liquidity and volume. Rules of thumb: order < 5% of visible bid/ask depth: minimal impact. Order 5-20% of depth: moderate impact, consider slicing. Order > 20% of depth: significant impact, definitely slice. Also compare to minute volume: order < 5% of average minute volume is OK as a single order; > 10% of minute volume means impact is likely, so slice it. Check both depth (immediate impact) and volume (sustained impact), and remember liquidity is split across ASX and Cboe. For SPI 200, 5 contracts is usually fine. For illiquid small-cap shares or far-OTM ETOs, even small size can be significant.
It depends on urgency and market conditions. Non-urgent: place at the bid (for buys) or ask (for sells) - you're adding liquidity and saving the spread - or rest a Centre Point order at the midpoint. Moderate urgency: place inside the spread (e.g. SPI 200 bid 8,700, ask 8,702, buy limit at 8,701) - better than an aggressive order, faster than joining the bid. Urgent: place at or slightly beyond the market; you'll cross the spread but still limit slippage. Very urgent: a Market-to-Limit (rare). General principle: start passive and get more aggressive as time passes. Never start with an aggressive order unless it's an absolute emergency.
Use TWAP when: the volume pattern is unpredictable, simplicity is preferred, you don't care about matching a benchmark, or you're in a low-volume period. Use VWAP when: you need to match/beat a VWAP benchmark, the volume pattern is predictable (normal trading hours), you want to blend in with the market, or for larger orders where matching flow matters. On the ASX, the close (CSPA) is itself a common benchmark, so routing balance into the closing auction is often the cleanest option for end-of-day targets. For most retail traders TWAP is simpler and works well; VWAP matters more for institutions benchmarked against it. If in doubt, TWAP is the safer choice.
Step 1: record the decision price (when you decided to trade). Step 2: record the arrival price (when the order was submitted). Step 3: record the execution price(s) (all fills, weighted average). Step 4: IS = decision price - execution price (for buys; reverse for sells). Track over time: calculate IS for every trade and average it by instrument, time period and size. Look for patterns. Improvement: if certain times/sizes have high IS, adjust your approach. Build a simple spreadsheet or log to track. Over 50+ trades, patterns will emerge.
Volatile markets mean wider spreads, higher impact and faster prices. Strategies: 1) Reduce size - trade smaller until volatility calms. 2) Widen limits - accept slightly worse prices but ensure fills. 3) Always use limit orders - an aggressive order in volatility can fill horribly. 4) Consider waiting - if the trade isn't urgent, let volatility settle (e.g. after an RBA release). 5) Slice more aggressively - break into smaller pieces over time. 6) Use IOC to test liquidity without leaving stale orders. Don't fight volatility. If your edge doesn't require catching exact moves, be patient and wait for calmer conditions.
Phased approach: Phase 1 (Manual): create a spreadsheet logging timestamp, instrument, venue, decision price, order type, limit price, fill price and size. Calculate IS for each trade and review weekly. Phase 2 (Automated logging): connect to the broker/exchange API, auto-capture fills, store them in a database and calculate metrics automatically. Phase 3 (Analysis): segment by time of day, instrument, size, order type and venue; identify patterns; visualise with dashboards. Phase 4 (Optimisation): use the insights to adjust execution, A/B test different approaches and measure improvement. Phase 5 (Integration): feed TCA insights back into the execution system so adaptive algos use the data in a continuous improvement loop. Start with Phase 1 - even manual logging provides valuable insights.
Key factors: 1) Order book imbalance - more bids than asks suggests upward pressure, so you may want to buy more aggressively. 2) Hidden liquidity - large orders and Centre Point midpoint flow may be hidden, so the price may not move as much as the visible book suggests. 3) Venue fragmentation - the true book is split across ASX and Cboe; route smartly. 4) Trade-flow toxicity - if flow is 'informed' (smart money), market makers widen spreads, so avoid trading in toxic flow. 5) Queue dynamics - limit-order queue position matters; earlier is better. 6) Time-of-day patterns - spreads, depth and toxicity vary by time. 7) Tick-size constraints - price moves only in ticks, which bounds how tight the spread can be. Practical application: observe these patterns and adjust execution timing and aggressiveness accordingly.
For orders > 20-30% of daily volume, multi-day execution is appropriate. Approach: 1) Plan the horizon - decide how many days (balance impact vs timing risk). 2) Daily targets - allocate to each day (e.g. 20% per day for 5 days). 3) Intraday algo - use TWAP/VWAP within each day, and consider routing a portion into the CSPA close. 4) Adaptive - if filling easily, accelerate; if causing impact, slow down. 5) Anonymity - use multiple venues/brokers where possible and vary timing patterns. 6) Monitor - track overall IS across the multi-day execution. Risk management: consider hedging during execution. If accumulating a long position, buy protective puts; if selling, consider calls. This protects against adverse moves during the extended execution.
ML applications in execution: 1) Volume prediction - forecast the intraday volume pattern for a better VWAP (features: time of day, recent volume, volatility, day of week). 2) Spread prediction - forecast when spreads will be tight and execute then. 3) Impact modelling - predict market impact from order size, urgency and conditions, then optimise execution to minimise it. 4) Optimal scheduling - given an order, horizon and conditions, ML suggests the best schedule. 5) Adaptive execution - real-time adjustment based on observed fills vs expectation. Implementation: start with simple models (linear regression for volume prediction) and graduate to more complex ones as data grows; always validate out-of-sample. Well-implemented ML can improve execution by 5-15% over simple rules.
Common advanced mistakes: 1) Over-optimisation - building complex algos that work in backtest but fail live due to overfitting; keep it simple. 2) Ignoring regime changes - execution that worked in low-vol may fail in high-vol; adapt to conditions. 3) Underestimating the adversarial nature - participants adapt to your patterns, so vary your approach. 4) Latency assumptions - assuming fills happen instantly; account for latency. 5) Neglecting rare events - a system that works 99% of the time but is catastrophic 1% of the time needs safeguards. 6) TCA cherry-picking - only analysing good executions; analyse the failures especially. 7) Complexity without testing - each addition should prove its value. 8) Ignoring explicit costs - focusing on slippage but forgetting brokerage and exchange/clearing fees, which add up even though Australia has no transaction tax. Solutions: systematic testing, conservative assumptions, continuous monitoring and honest analysis.
Full guided lessons, quizzes, and a complete strategy library for the Australia market. One-time purchase. No subscription, ever.
Get Australia access →