spreadbetting wrote:It'd be a very simple way of making money if this Brownian motion was guaranteed to cross the spread and take our market making positions then reverse direction. Sadly the only guarantee you can expect by random market making is 100% of your losing bets will be taken.
Let's say that, whilst you don't know what the market will do next, you predict that it's going to remain in a range for a while. So you offer within the range, and let's say your back bet gets taken.
Two things can happen here (assuming that matters are brought to a conclusion before the race goes in-play). Either the market stays within the range and also takes out your lay offer, giving you a small profit, or it exits the range and you exit the trade with a small loss.
If it's the latter, it's not the end of the world. After all, it's widely believed that, by trading at random, you'll near as dammit break even, so you won't lose much long-term with such an approach. But if there's some objective basis for believing that the market will remain range-bound and that the market will exhibit Brownian motion within the range, then maybe you will cross the line to profitability.
Personally, I prefer to swing for the fences and go for nice trends than to adopt such an approach, but some people may be able to profit by predicting volatility and offering money within a market they think will remain range bound. You're not going to make many ticks' profit per trade, but that could be compensated by you potentially getting lots of trades through the market whilst it remains stuck within its tight range.
Jeff