What you told is correct that holding bitcoin is the very good option as you can see that bitcoin is reaching all highs and price is moving high but we cannot say it is risk free because what if the price drops in long time like sudden their is some bad news and views , then the price will drop so it is risky in both option trading or holding.
That's right and need to consider the risk, both is profitable, also have risk but the level of risk is different, holding have less risk because altcoin easy to manipulate, but you can earn big profit if you know the trends and research more to altcoin which have bright in the future.
I prefer do both.