Ok, here is how I am going to structure new investments:
Any investors who invest over 10 days will have their BTC locked to USD as explained previously anyone with 10 days or below will have there investment locked to BTC as investments were previously, this way there will be less time for BTC to rise greatly and for me to reduce losses.
This method will minimize the losses for investments with long payout intervals - but at the same time, still allow investors to adjust and profit.
This sounds like a great plan.