Try some ICOs lending. High risk high return.
I would not advise that one. It's better if he enters trading because it's less risk but much faster way of growing your btc. This is the year where a lot of forks has happened that I have take advantage of the highs and lows of btc and altcoins so trading really works.
Trading is also a high risk way of making money, that requires you to be knowledgeable in order to succeed in trading and never expect easy money because the result will always depend on your decision making. You can grow your bitcoin in trading but it will take time, you need to continuously learn and develop yourself to become expert in trading for better chance.