Mid Price
Mid price is the average of the best bid and best ask. It is often a better proxy for consensus than last traded price in thin markets.
Definition
Mid price is the average of the best bid and best ask:
mid = (best_bid + best_ask) / 2
Why it matters
In thin markets, the last traded price can be stale or misleading. Mid price updates whenever the book changes and is often a cleaner proxy for market consensus.
Related
Mid price is commonly used to compute implied probabilities and to create benchmarks such as a consensus snapshot at a given time.