SBs rarely misprice in the punters' favour. If you've been doing well without a system you probably have a system. But allow me to ask you, how long have you been operating this way and how many trades have you placed? What's your Win:Loss ratio?
I ask not out of impertinence, but with a sneaking suspicion. The suspicion is, if you’ve been doing this successfully for more than 12 months, you probably do have a system and haven’t realised it. If you’ve been doing this successfully for less than 12 months, you may have a system, but I wouldn’t be thinking about increasing stake size yet – certainly not until you’ve identified objectively what it is you are doing. It’ll take all the fun out of it, but I’d be looking to understand what it is I’m doing from an objective viewpoint so that I could make sure I had a system that acknowledges what action I need to take and not take under any circumstance. Especially the bit that says ‘stay out until you know what’s really going on’.
As for going from £30/day to £150/day it’s not going to raise a ripple on their radar. Yet.