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2019issue C0745

Paper trading is unfinished without fill and size rules

Retail paper-trading platforms often omit live-market details, so a clean simulator run can still diverge from live execution. Editorial view: the run is not a live-ready-procedure until limit-order fill assumptions and fixed-contract-sizing sit in the same ruleset as the signal.

  • Retail paper-trading platforms often omit live-market details, so a simulator result can diverge from live execution.
  • A limit-order touch-fill, granted as soon as price is touched, is treated as an unrealistic fill model and can change outcomes versus live fills.
  • Automated paper-trading can fail after go-live when placement, cancel and replace, or session setup is incompatible, including a session-open-reject.
  • A first live step uses fixed-contract-sizing with micro forex lots, a few shares, or mini or micro futures rather than full-size contracts.
Entries in this reading3 entries
Paper trading simulation3 readingsLimit order4 readingsCurrent trackFixed contract sizing29 readings

A clean simulator run is an unfinished test

Paper-trading is a simulated run of entry, exit, and abstention rules used to make a procedure checkable before capital is at risk. Retail paper-trading platforms often omit live-market details, so a simulator result can diverge from live execution.

Editorial view: treat that clean run as an unfinished system test. A live-ready-procedure is the combined signal, order-lifecycle, and size rules that must hold in both simulated and real-money modes.

Touch-fill is an incomplete limit-order test

A limit-order waits for a specified price and may go unfilled even if that price is touched, so fill quality belongs in the system test.

A limit order that fills in simulation as soon as price is touched is treated as a sign of an unrealistic fill model, because such touch fills are uncommon in live trading. That pattern is a touch-fill: a simulator fill granted as soon as price reaches the limit, which live books often do not grant.

The same strategy can produce different outcomes under simulated limit-order touch fills than under live fills.

Same ES 60-minute strategy: simulated vs live equity

The simulated equity path climbs from about break-even to roughly $4,400 over about 330 trades, while the live-money path of the same @ES 60-minute ruleset trends down to about −$1,250. A trader should treat the left-hand run as an incomplete limit-fill test, not a live-ready result. Points were read off the two magazine equity-curve panels; they are approximate.
The simulated equity path climbs from about break-even to roughly $4,400 over about 330 trades, while the live-money path of the same @ES 60-minute ruleset trends down to about −$1,250. A trader should treat the left-hand run as an incomplete limit-fill test, not a live-ready result. Points were read off the two magazine equity-curve panels; they are approximate.@ES · 60 min · 2019-03-21T00:00:00.000Z to 2019-05-03T00:00:00.000Z

Digitized from Figure 1. The source labels both panels @ES 60 min from 21 March 2019 19:00 to 3 May 2019 17:00 and attributes the gap to simulated limit-order touch fills versus live fills. Readings are to the nearest roughly 50–100 dollars and about 10 trades; the raster does not support finer precision.

Automation still fails on the order lifecycle

Automated paper-trading results can fail after go-live when order placement, cancel and replace handling, or session setup is not compatible with live trading.

A market order sent a split second before a new exchange session may fill in simulation and be rejected by the exchange in live trading. That live rejection is a session-open-reject: a live exchange rejection of an order timed just before a new session that a loose simulator may still fill.

Real-money stakes change the same rules

Real-money stakes change decisions relative to simulation, and automating the signal path does not remove that effect.

Cap the first ticket before leaving simulation

Fixed-contract-sizing is a pre-entry cap on contracts, shares, or lots that keeps loss and exposure bounded when leaving simulation. A first live step keeps size bounded with micro forex lots, a few shares, or mini or micro futures rather than full-size contracts.

One micro equity-index futures contract is described as one-tenth the related mini contract and as 1.25 dollars per tick. When even a small account is not feasible, some firms offer funded capital after a fee-based simulator test that meets a stated hurdle.

Editorial view: the size cap is not a later operations detail. It belongs in the same live-ready-procedure as the paper-trading rules and the limit-order fill model.

Educational research material, not investment advice. Historical source context does not establish present-day performance.
20 of 21 in the Fixed contract sizing track
201917-17 pp.Next on Fixed contract sizingConstructing futures leverage from margin and fixed sizeA listed futures trade is a standardized delivery obligation, not an immediate transfer of the commodity, and it can be closed by offset before expiration.
All readings on this track · 21 readings
  1. 1987Volatility-layered mechanical system with fixed contracts
  2. 1994Starting capital from worst-case portfolio walk-forwards
  3. 1994Bound small-account risk before adding leverage
  4. 1996Variable position size after entry
  5. 1996Equity path filters for contract size and drawdown
  6. 1997Stop distance, equity caps, and trading halts
  7. 1999Size-matched buy-and-hold evaluation for stock systems
  8. 2002Size from stop distance to keep dollar risk even
  9. 2003Share size from daily profit equilibrium
  10. 2004Half-size energy futures as a pre-trade leverage filter
  11. 2007Equalizing contract risk in trend following
  12. 2007Expected-equity sizing and geometric drag
  13. 2007Predefine the loss before fixed contract sizing
  14. 2013Weekday, session, and market expectancy for contract size
  15. 2014Bounded leverage before you size a trade
  16. 2015Equal-dollar futures size and open-interest liquidity
  17. 2015Atomize trading decisions: discipline over complexity
  18. 2017Tiny bets, ruin risk, and mechanical scale
  19. 2018Near-strike weekly puts and unfunded assignment risk
  20. 2019Paper trading is unfinished without fill and size rules
  21. 2019Constructing futures leverage from margin and fixed size
By fieldSystem design117 readingsBy year201975 readings
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