Quote from momoneythansens:
Sorry, I wasn't clear, even in my edited version! You're too quick on the response.
If your short strike is at say 1340, i'm suggesting you might want to consider hedging early e.g from 1310 perhaps. As the underlying moves towards your short strike, you can feasibly win on both the hedge and the credit spread if it expires worthless. This is what Riskarb calls convergence gains. It's a pseudo-short straddle at 1340.
Hedging earlier also means needing less contracts and thus reduces whipsaw risk.
The problem is, it's very tempting to leave the hedge too late.
You may also wish to consider static hedges e.g. long strangles that don't require constant babysitting. These will have the effect of reducing the credit received as a matter of course but with friendlier risk profiles.
Good luck.
MoMoney