How does the robot trade volatility? I can't wrap my head around the concept. Is it a transparent algorithm where you understand the logic or is it a black box where you have to trust the developer?
Does it have any parameters you can tweak?
I use this one, just posted it: https://bitcointalksearch.org/topic/goxtool-bot-range-trading-376352
If you know or can hire a programmer, you can implement your own logic, this one here works good for me. It's for MtGox, through a simple to use opensource goxtool that is used for various trading bot strategies. You will have to create API key for trading in your Gox panel and add it to the bot. You need to rent your small server from some VPS provider so that the bot would be trading 24/7, here it is $5 per month, can't beat that: DigitalOcean
Range trading is very simple - you buy below current price and sell above, inside some preset range. You split your range in lines, where you would be buying/selling. You only need to adjust the range when you believe market conditions changed. Mine right now is 450-900, if we break 900 (and the bot would've sold all btc by then) I will adjust it to be 650-1350 and the bot will buy some btc on a swing down and continue range trading, it would quickly balance btc with fiat again.
It does not try to guess where the price would go. Just buy 480 - sell 520, rinse repeat, so profiting from any volatility inside a range. The smaller the range you set (and the more money you get on gox) - the bigger the trades it makes, so more yield.