Abstract: This invention relates to alternative, synthesisable trend-following strategy, based on a rolling, delta-spliced lookback straddle. This operates like a conventional lookback straddle, except that the time to expiry, rather than monotonically running down to zero, is reset where possible to that of a ‘younger’ straddle, provided that the delta of the two straddles does not differ by more than a specified amount. It is more computationally efficient than prior art approaches; further, it does not lead to positions being prematurely liquidated.