RuleTrader takes account of all costs during back-tests, to provide a realistic, conservative view of the performance of your trading system. The Trading Costs tab is where you control how these costs are calculated.

Average Spread Calculations: Average spreads are calculated for a share by weighting each bid-offer spread by the time that spread is available, to produce a time-weighted average spread for the day. Each day’s average spread is then averaged over the period specified here.

As spreads are often significantly higher at the beginning and end of the trading day, these settings allow you to ignore the spreads quoted just after market open and just before market close. Not all shares have bid-offer data available, so the final setting in this group is the default average spread that is used instead. Set this to the worst case for the type of shares you expect to back-test.

Levies & Duties: These settings concern the calculation of Stamp Duty and the PTM Levy. These will not normally need altering unless there is a change in the relevant laws.