Binance trading is tricky, i wonder if it's SCAM??

[kennyy2929]

i keep my eye on binance and do some test.
i have check coinmarketcap price and binance price for IOTA yesterday, while coinmarketcap is at $3.2 and binance is at 3.4 and keep rising. i wonder why is this so weird. so i try to trade a little amount something like $20, once i done the trade, the price just DROPPED to 3.2 same like coinmarketcap.
I wonder is this a technic of binance to trick those who are trading? is this some scam??