Fed Week Turns Slippage Into a Position-Size Input

Slippage belongs in the pre-trade loss budget during Fed week. Treating it as an after-the-fact complaint understates risk when policy headlines can move the quote beyond a stop or entry before the order reaches executable liquidity.

The facts are concentrated. August CPI rose 0.4% month on month and 3.4% year on year. The Fed's two-day meeting begins September 15 and ends September 16. Reuters reported on September 14 that the dollar index reached its highest level since September 2 as oil and rate expectations moved. None of this predicts the decision. It establishes a high-attention window.

Stress the fill, not just the trigger

Suppose a position risks $200 at a 20-pip stop under normal execution. If a release widens the effective exit to 32 pips, the same volume risks $320 before spread and commission. The position should be resized from the stressed distance if $200 is the true account limit.

No universal slippage allowance is credible. Build it from the account's own history for the same pair, order type and event class. If the sample is thin, use conservative scenarios or skip the release. A broker's maximum-deviation setting may limit some entries, but it cannot force a stop to fill where no price is available.

The CFTC notes that an OTC forex customer trades against the dealer and is limited to the conditions it offers. That makes provider documentation and personal deal history more relevant than a generic interbank-liquidity claim.

The September 13 weekly outlook helps map the week's scheduled events. It is planning commentary, not execution evidence.

The risk loop closes before the order is sent. Add the stressed fill to the stop distance, calculate cash loss, then choose volume. If the minimum trade size still exceeds the limit, the account is too small for that event setup.

Sources

• BLS: August 2026 CPI
• Federal Reserve: September meeting calendar
• Reuters: dollar gains before the Fed
• CFTC: OTC forex execution risks

Scenarios are illustrative. Historical slippage does not cap future execution loss.