Auditing Your Trading Costs, Where Your Profit Quietly Goes
Many traders know their win rate but not their costs. Over months, spreads, commissions, swaps, and slippage can quietly consume a large part of profits.
How to do a cost audit:
Step 1: Gather your last 50 to 100 trades. Include pairs, sizes, and times.
Step 2: Calculate spread cost. For each trade, multiply the average spread in pips by the pip value and lot size.
Step 3: Add commissions and fees. Take them from your statement.
Step 4: Add swap charges for trades held overnight.
Step 5: Estimate slippage. Compare intended entry and exit prices with actual fills.
Step 6: Sum everything. Compare total costs to your gross profit or loss.
What you might learn:
- Trading during low-liquidity hours costs more
- Small targets are heavily affected by spreads
- Some pairs or brokers cost much more than others
- Overtrading multiplies costs
How to reduce costs:
1. Trade active sessions with tighter spreads.
2. Choose liquid pairs.
3. Reduce trade frequency.
4. Aim for larger targets relative to costs.
5. Compare brokers regularly.
An edge must exceed costs to be real. If your edge is small, costs may erase it.
Know your numbers, and you'll know where to improve.
Auditing Your Trading Costs, Where Your Profit Quietly Goes
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LondonNewsTrader
- Posts: 421
- Joined: Mon Sep 21, 2026 9:30 am
Re: Auditing Your Trading Costs, Where Your Profit Quietly Goes
For step 2 on spread cost, I'd measure the spread at the moment of each fill rather than using an average. Spreads are not evenly distributed through the day. If most of your trades were taken in London and New York hours, the average is fine. If some were taken in the minutes after a release, or near the 5 p.m. New York rollover, those individual trades will have paid several times the normal spread, and an average hides that.
MT5 can show this if you export the history with the bid and ask, or you can record the spread at entry by hand for a month. When I did it, the trades taken within five minutes of a major data release paid around four times my normal spread on average, and that one category accounted for a big share of my total costs.
Your point that an edge must exceed costs is the whole thing in one sentence.
MT5 can show this if you export the history with the bid and ask, or you can record the spread at entry by hand for a month. When I did it, the trades taken within five minutes of a major data release paid around four times my normal spread on average, and that one category accounted for a big share of my total costs.
Your point that an edge must exceed costs is the whole thing in one sentence.
Re: Auditing Your Trading Costs, Where Your Profit Quietly Goes
A thing I noticed when I did my own cost audit: swaps were the surprise. I'd held a few trades over several nights on the wrong side of the carry and it added up to more than I'd guessed. Worth checking that column specifically if you ever hold overnight.
It’s Fairman 
Re: Auditing Your Trading Costs, Where Your Profit Quietly Goes
Another thing that came out of my audit: trading the session open on certain pairs was costing more than I thought because spreads were still wide. Moving my entries 15 minutes later cut costs a bit without changing the strategy. The London open is 8am Lagos in summer, and on pairs like GBPJPY or EURAUD the spread in the first few minutes can be double what it is by 8:15. The same happens at the Tokyo open and around rollover at 10pm Lagos. If your platform lets you export the spread at entry, sort your trades by entry time and compare the average spread for each hour.
It’s Fairman 