user77765: What do you think is there possibility to write crypto bots using spread beetwen asks and bits? For example: buy currency X for 0.025BTC and then sell X for 0.026 BTC in the same exchanges. As a result we have 4% profit - 2*0.25% (exchanges fee) = 3.5% 

user75001: You may rest assured that this is widely happening already, not just with Bitcoin and crypto-currencies, but with other currency markets and the stock exchange.

77765: <p>What do you think is there possibility to write crypto bots using spread beetwen asks and bits? For example: buy currency X for 0.025BTC and then sell X for 0.026 BTC in the same exchanges. As a result we have 4% profit - 2*0.25% (exchanges fee) = 3.5% </p>
 75001: <p>You may rest assured that this is widely happening already, not just with Bitcoin and crypto-currencies, but with other currency markets and the stock exchange.</p>
