CME Group的合約規格中提到TAS和TAM交易，如：
Gold Futures Contract Specs
Gold 期貨 合約規格
Trading at Settlement (TAS) is allowed in the first ,second ,third and fourth nearby active contract months- February, April, June, August and December. TAS transactions may be executed at the current day’s settlement price or at any valid price increment up to 10 ticks higher or lower than the settlement price.
TAS trading terminates 3 business days prior to the contract month.
以結算價交易（TAS）可在有效合約月份進行。有效合約月份為2月、4月、6月、8月和12月。TAS交易可按當日結算價或高於或低於結算價十個最小波動單位的任何有效價格增幅進行。TAS交易在合約月之前3個營業日終止。
Trading at Marker (TAM) is analogous to our existing Trading at Settlement (TAS) wherein parties are permitted to trade at a differential that represents a not-yet-known price. TAM trading will use a marker price, whereas TAS trading uses the Exchange-determined settlement price for the applicable contract month. As with TAS trading,parties enter TAM orders at the TAM price or at a differential between one and ten ticks higher or lower than the TAM price. Trading at Marker is available for the London p.m. Marker on the nearest active month ( February, April, June, August, December).
以市價交易（TAM）易類似於我們現有的 TAS 交易，允許交易各方以未知的價差交易。TAM 交易將使用市場價格，而TAS 交易使用交易所為適用的合約月確定的結算價。如 TAS 交易一樣，TAM交易各方將能夠以TAM 價格或上下加減1至10個最小波動單位差價輸入 TAM 交易單。
市價交易適用於倫敦下午時間最近的活躍月份（2月、4月、6月、8月、12月）。
英文摘自：https://www.cmegroup.com/trading/metals/precious/gold_contractSpecs_futures.html
中文摘自：https://www.cmegroup.com/cn-s/trading/metals/precious/gold_contract_specifications.html
那么什么是TAS呢？
Trading at Settlement (TAS)
TAS is an order type that allows you to execute at a spread to the settlement price at any time during the trading session. You can enter TAS order types up to 8 ticks above or below the settlement price, depending on the contract.
TAS是一種報單類型，允許你在交易階段的任一時刻采用結算價或包含一定價差的結算價進行報單。
Key Benefits
Reduce uncertainty around the settlement price
Price contracts at or near the settlement value
Execute at any point of the trading day rather than waiting for the market close
Available on CME Globex and eligible for block trades
主要優勢
降低圍繞結算價的不確定性
合約采用結算價或結算價附近的價格
可以在交易日中的任何時間點執行，而不必等到收盤
CME Globex和大宗交易中可用
英文摘自：https://www.cmegroup.com/trading/trading-at-settlement.html
中文自翻，僅供參考