{"e":"contractInfo",// Event Type"E":1669647330375,// Event Time"s":"APTUSD_PERP",// Symbol"ps":"APTUSD",// Pair"ct":"PERPETUAL",// Contract type"dt":4133404800000,// Delivery date time "ot":1666594800000,// onboard date time "cs":"TRADING",// Contract status "bks":[{"bs":1,// Notional bracket"bnf":0,// Floor notional of this bracket"bnc":5000,// Cap notional of this bracket"mmr":0.01,// Maintenance ratio for this bracket"cf":0,// Auxiliary number for quick calculation "mi":21,// Min leverage for this bracket"ma":50// Max leverage for this bracket},{"bs":2,"bnf":5000,"bnc":25000,"mmr":0.025,"cf":75,"mi":11,"ma":20}]}