prev_day_level targets the prior trading day's high or low. The thesis: those levels are visible to other participants and often act as magnets or rejection zones.

Shape

"take_profit": {
  "type": "prev_day_level"
}

Fallback rule

When the prior-day level is on the wrong side of entry (e.g. price already cleared yesterday's high before the trade opened), the engine substitutes a 2× the typical stop distance target so the trade still has a sensible target instead of failing.

Usage

Common in strategies that treat previous-day-high and previous-day-low as reference levels - many participants react around these prices.

Pitfalls

Crypto runs 24/7. "Previous day" boundary is at 00:00 UTC. If your strategy mental model uses a different daily boundary, the level will surprise you.
The fallback is silent. Check the trades table to see how often the fallback fired vs the prior-day level was used.