Brokers ship raw fills (individual BUY/SELL rows), not finished round-trips. TradeOnyx pairs them via FIFO into trade rows you can analyse. The trading-style preset adds a pre-step that decides which same-side fills belong to the *same* open position.
Four presets:
* Default – no merge. Each fill stands alone. This is the original behaviour and the safe baseline. * Scalper (30 s) – only true rapid-fire fragments collapse: a broker that splits one click into three fills inside half a minute becomes one open instead of three. * Swing (24 h) – a same-day scale-in is one position. BUY 100 at 09:00, BUY 100 at 15:00 → one BUY 200 with volume-weighted entry price, and the later SELL 200 closes it as a *single* trade rather than two. * Custom – any window from 0 s to 7 days. Power users dial the exact threshold their strategy needs.
Only opens are merged. Closing fills always stay individual so partial take-profits keep their realised P&L.
The preset is global, stored on your user settings, applied identically to CSV uploads and broker auto-syncs. Switching it does not rewrite trades you already imported — only the *next* import sees the new window. Re-import an account if you want the existing history reshaped.
Pick by honest self-assessment, not by what sounds powerful:
* If you click once and the broker fragments the fill, you are a Default user with bad broker behaviour. Scalper preset fixes the cosmetic noise without changing your psychology. * If you scale into a thesis over hours, Swing is mandatory — otherwise the Onyx-Engine sees three small trades instead of one position and the discipline detectors read your behaviour wrong. * Custom only if you have a measured reason (e.g. "my futures setup builds in three 5-minute waves, exactly 600 seconds is right").
Where to set it: Open `/dashboard/import` and scroll to the Trading style row above the Import button. Click your preset; the value persists immediately. Custom mode reveals a *merge-window (seconds)* input.
What you should verify after switching to Swing: Re-open the Trades tab and confirm the count went down (one large position vs. three small ones) on the affected period. If the count is unchanged, your fills were already individual scale-outs (Default behaviour was already correct for you).
Re-imports: if you want to reshape your existing history under the new preset, delete the affected account's trades + re-import the CSV. The merge runs identically against the same fills.