Week 2 Session: How a Stock Trade Actually Happens
Placing and tracing a simulated stock order end to end, from order type to fill
Session
1 March 2027
An order-diagnosis session applying Week 2’s market/limit-order and bid/ask distinction to two orders you place yourself.
What you’re given
The simulated account from Week 1, live simulated bid/ask quotes on a shared instrument, and the two order types from this week’s lecture: a market order (fills now, at whatever the best available price is) and a limit order (fills only at your price, or not at all).
What you do
Place a simulated market order and a simulated limit order on the same instrument, then diagnose the gap between them: where each one filled, why the market order paid the ask rather than the mid-price, and whether the limit order filled at all.
What you produce
Both simulated fills (or the limit order’s non-fill), plus a short written diagnosis of why they differ — this is the gap the session exists to make visible, not a side effect of it.
Why it matters
That diagnosis feeds directly into the Market Mechanics Notebook, and Week 3 assumes you already have a simulated order to reflect on.
The spec
What you bring to the session. Written so a reader can tell whether it has been met without asking you.
- places at least one simulated market order and one simulated limit order
- can explain, for their own simulated order, why it filled where it did
Teaching team
- Idris Fenn — tutor