Position Monitor
Open a run from MesoSim Backtests, then select Position Monitor. Use it to inspect an individual position's Profit and Loss (PnL), Greeks, and Risk Graph as the backtest progresses. The accompanying price chart shows the underlying and, where available, VIX.
Navigate positions and time
- Choose a Position from the dropdown, or use the previous/next position buttons.
- Move the time slider or use the previous/next frame buttons to step through recorded snapshots.
- Check As Of for the selected timestamp. The time markers on the PnL, Greeks, and underlying-price charts move with the selected frame.
On smaller screens, the controls and charts are stacked vertically. The same position and time controls remain available when the run has recorded traces.
For example, select a position whose delta changes after an adjustment. Move through its recorded snapshots, then use Events Viewer to inspect the trades and variables behind the change. The delta-hedging guide provides an adjustment example.
Configure trace collection
Trace collection defaults to Daily. It records the snapshots used by Position Monitor. Set the interval before submitting the run, using Settings.Sim.PositionMonitor in the Strategy Definition.
This JSON fragment belongs inside your existing Strategy Definition; retain its other settings:
"Settings": {
"Sim": {
"PositionMonitor": {
"TraceCollectionInterval": "Daily"
}
}
}
| Interval | Recorded snapshots | Use it for |
|---|---|---|
Off | No recorded risk traces | Runs where you do not need to step through positions |
Daily | Entry, session close, and a final snapshot when a position closes | Reviewing positions across trading days |
Hourly | Entry, scheduled hourly snapshots during the session, session close, and a final closing snapshot | Inspecting changes within a trading day |
Hourly snapshots follow the session's sampling schedule; the hourly sequence is not restarted at each position's entry time. More frequent collection adds work to the backtest. See Accounts and Access for plan coverage of hourly traces and HD Risk Graphs.
Preferences
Save a per-symbol Trace Collection Interval in MesoSim Preferences. The Preferences guide explains how those defaults apply to Simple run, Templated run, and symbol changes in the AI Editor.
To change trace collection for an existing result, clone the backtest, update the interval, and run it again. Changing preferences does not add snapshots to a completed run.
Interpreting Risk Graphs
The 2D Risk Graph projects PnL across underlying prices at selected time horizons, through the first option expiration in the position. The PnL and Greeks history charts show values recorded during the simulation. Use the selected As Of timestamp to compare the projection with the recorded position state.
Risk Graphs use the open legs and valuation inputs at that frame. A projection does not simulate future adjustments or exits. Check backtest results and events to see what the strategy actually did.
Time projections
Select the 3D button to view projected PnL and a chosen Greek across both underlying price and time, through the position's last option expiration. Use the Greek selector to switch between Delta, Gamma, Theta, Vega, and weighted Vega.
This is particularly useful for structures with multiple expirations: you can see how the projected shape changes as the earlier legs expire.
HD Mode
The HD button switches the Risk Graph's valuation mode. HD projections account for non-trading time and adjust Implied Volatility around weekends and holidays. Deltaray's Position Monitor introduction explains the modeling approach with examples.
HD requires recorded traces. Switching HD changes the displayed projection; the trace collection interval determines how many historical snapshots are available to inspect.
For using projected values in strategy logic, see Options Valuation Model.
When only a limited view is available
If recorded traces are unavailable, Position Monitor can use suitable event-log data to approximate the first frame of a Risk Graph. In this mode, position/time navigation and the history charts are unavailable, and HD cannot be enabled.
Clone and rerun with Daily or Hourly trace collection to inspect the position over time.