Mark Price

To calculate unrealised profits and losses in future contracts, not always the last traded price of the future is used.

If the last traded price is not within the current best bid-ask, then the bid price or ask price will be used, whichever is nearer to the last traded price.
Further the mark price can never differ more than 10% from the Deribit BTC index +/- implied interest rate (which we call the ” fair price” for the weekly future, or when in last half hour before expiration, the estimated delivery price. These rules will prevent liquidations due to manipulative trading.

Examples:

1.
INDEX=870.00
BID/ASK= 871-871.50
LAST= 871.70

The Mark Price for calculating profits/losses in future contracts will be 871.50

2.
INDEX=870.00
BID/ASK=871/871.50
LAST= 871.20

The Mark Price will be 871.20

This post is also available in: Chinese (Simplified)

Example (futures)
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