bitcoin trading is entrust the majority of investment you have to buy be some bitcoin, then you sell it back. such that is rotation of bitcoin. while the risk is you will get a reduced amount of bitcoin as a prediction in the buying and selling bitcoin.
In essence, that's it, but to give a more complete answer to the OP, we have to say why it is so risky. The risk lies in the fact that the BTC market does not have very high liquidity when compared to the most common currencies. This brings some instability to the market, and it is one of the main causes of high volatility. This problem requires time to be resolved, since it is not yet common to see people buying and selling things using Bitcoin.
bitcoin trading for me it is not so risky compare to gambling casino it is less risk than gambling you can get more profit in trading with less risk unlike in gambling high risk low profit.. because of ods,. and if you lose you can not recover back some of your loses.,, unlike in trading that if you lose only the price and patience is your lose..