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Paper vs live differences

Nocterm runs orders in one of two modes. In paper mode your fills are simulated against the live order book - no real money changes hands. In live mode your orders go to the exchange for real. The two feel almost identical to trade, but what happens behind the fill is very different. This page lays out exactly how they differ.

Modes: Paper / LiveSwitch: trade panel mode selector
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id: help-paper-vs-live

The trade panel in paper mode next to the same panel in live mode

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Paper is a realistic rehearsal. Live is the real thing. Paper simulates fills against the same live order book live trading uses, so price action and fill behaviour look authentic - but there is no money at risk and no real exchange fees. Live sends your order to the exchange, where it fills against real counterparties at real cost.

PaperLive
Money at riskNone - simulated balanceReal funds on the exchange
FeesOnly what you model in the simReal exchange fees and any rebates
Fill realismSimulated against the live bookActual exchange fills
LatencyLocal, near-instantRound-trip to the exchange via the desktop client
Needs desktop clientNoYes - the client bridges to the exchange
On client disconnectn/aFalls back to paper

Paper fills are modelled against the live order book - the same depth live orders see - so a paper fill at a wall or in a fast market behaves much like the real thing. What paper does not charge is real money or real exchange fees: any cost you see is whatever the simulator models, not an exchange invoice.

Live fills are exchange fills. They cost real money, pay real fees (and earn any maker rebates), and are subject to the exchange’s own matching, minimums, and rejection rules.

Paper resolves locally, so fills feel near-instant. Live has to make a round trip out to the exchange - through the desktop client - and back, so there is genuine latency between sending an order and seeing the fill. In fast markets that gap matters, which is one thing paper cannot fully reproduce.

Live trading depends on the desktop client being connected. If the client drops, Nocterm falls back to the paper sim rather than failing your order outright. That keeps you working, but it also means a live order placed while the client is offline is a paper fill - so watch the connection status dot.