Really depends on your risk appetite and the available cash you have on hand.
Any individual should be diversified to have various degrees of income. Apart from your main source of income, whatever that maybe.
There is active & passive.
- Property investments
- Private Equity (“less” risk vs VS, and more stable returns)
- Venture Capital (more risky, higher returns / or complete loss)
- You can actively trade for yourself, stocks, options and forex.
- Or get someone to trade for you.
- As mentioned in the OP P2P
- Hold “hard assets” such as precious metals.
- Or just get someone credible to manage your spare cash.
And after all of this, it will depend on your risk appetite, as mentioned earlier.