Simulate changes on your real positions

How Both mode merges your held positions with simulated edits, so you can preview a hedge, a roll or a close against the dimmed base curve before acting.

The modeler's most powerful use is on the book you already hold: load your real positions, then model a hedge, a roll or a close on top of them and see the consequence before you place anything. Nothing you model is ever sent to your broker, because the canvas is a sandbox.

The three modes

• Sim — simulated legs only. Held positions stay out of the picture (they're preserved, just hidden from this view).
• Live — your selected held positions, exactly as held, read-only.
• Both — the merged view: held legs and simulated legs price as one book, and held legs become editable so you can preview changes to them directly.

Live and Both need a connected brokerage. The mode control sits in the top row of the Position Modeler page.

Loading your positions

• ↻ My positions pulls the latest from your broker and loads your held book onto the canvas. The modeler works one underlying at a time, so if you hold several it loads the first and says so.
• “Load broker's positions” opens a scope picker of your held structures, grouped by type. Tick any subset and load just those. This is the way to study one iron condor out of a busy book.
• Held legs are marked with your average cost and, when available, live market marks, so the P&L shown anchors to what your broker reports.

Modeling on top

• Add simulated legs exactly as in Sim mode: ruler clicks, the Add + catalog, drags.
• Edit held legs directly in Both mode: hover a chip for the ± steppers (they step through zero, so a held short can be flipped in preview), or open the leg card to change quantity, strike or expiry.
• Preview a close without deleting: open a leg's card and click Hide. The leg stays on the strip, dimmed, but drops out of the curves. Show brings it back.
• The "vs base" overlay draws your unedited held book as a dimmed curve behind the modified one, so every edit shows its consequence against what you actually hold. A ✎ notice appears whenever the canvas differs from your held positions.
• Done experimenting? Reset (or ↻ My positions) restores the book to exactly what you hold.

Simulated legs live only in the modeler. The app places no orders; when you decide to act on what you modeled, you place the trade at your broker as usual, and it flows back into the app with your next sync.