Rounds and markets

60-second binary markets, and the identifier that is safe to cache.

Omnibook runs a continuous series of 60-second rounds on the BTC price. Each round fixes a strike, trades for its window, then freezes and settles against the oracle price.

Lifecycle

status	Orders?	Meaning
trading	Yes	Open for trading
frozen	No	Trading closed, awaiting settlement
proposed	No	Settlement proposed, awaiting finalization
settled	No	winner decided, contracts paid
void	No	Round voided — contracts split per venue rules

Anything still resting when a round freezes is cancelled for you.

round_number vs market_id

market_id is recycled. round_number is not.

The venue draws market_id from a small pool and reuses values as rounds complete, so the same market_id will refer to a different round later. It is the parameter that order and orderbook endpoints take, but it is not an identity.

Key your own state — open orders, positions, PnL history — on round_number, which is monotonic and never reused. Re-read the round before acting on a cached market_id, or you will eventually place an order on the wrong round.

Prices

strike and settle_price are integers in units of 1e-8 USD. A strike of 6399240000000 is $63,992.40.

Contract prices are different: integer ticks from 1 to 99, in cents, representing implied probability. See Placing orders.

Settlement

At freeze, the round’s settle price is a true time-weighted average (TWAP) of the sequenced oracle BTC price over the last N seconds of the round (default N = 10, or per-series via twap_window_by_category; each round row exposes the resolved twap_window_secs). winner becomes "yes" if that TWAP is strictly above the strike, "no" otherwise (exact equality settles "no"). Winning contracts pay 100¢, losing ones 0¢.

fresh_source_count_at_freeze reports how many independent price sources were live at freeze — useful if you want to weight your confidence in a settlement.

Reading rounds

GET /v1/rounds?limit=1        # the current round
GET /v1/rounds/{round}        # one round
GET /v1/markets?status=trading

GET /v1/rounds?limit=1 returning status: "trading" is the normal way to find what to trade right now.

Categories

category groups rounds into series. Today the BTC 60-second series is category 1. Filter on it if you only care about one series.