Now bitcoin price cross 11500$. i want to buy some bitcoin for long hold. Is it safe?

it was the right time to buy for you a bitcoin where the price drops it means the price is very affordable compare to past days. You will start at that amount. Then make it grow by just holding it for a longer period even many months. And wait that price will goes up and your investment value will also grow. You need to be patience since it was very a long days to wait.