I’m holding a small bet at very long odds on a horse running in the Epsom Derby. I want to lay some off for a profit later in the week when the runners are finalised (probably at 48 Dec) but I’m concerned about when Betfair will change the market from being Ante Post. At the moment I can lay off against my potential winnings but when the market goes day of race I’ll have to put thousands into my account, to cover supposed losses on that market, which I don’t want to do if possible. Does anybody know when is the latest time I can still lay against my potential profit?