How about an auto increase or decrease on win? like you have for loss to use the multiplier.
Example...
Loss - use multiplier (eg 2) for the next be....
Win - increase or decrease the bet if desired (eg on win halve the bet instead of dropping to base bet)
Or some other little options along those lines.
We already have that function, but it's a bit safer... it increases based on the amount of currency it takes to stay at the current max loss streak without going over.