You can try to buy fund or stock.
Actually, if you plan to invest in fund, try to aim the target to 10+ years,
although you can select a 5 years plan, however, the return might be lower.
And usually lump si, investment, 40,000 it should be ok
如果是基金的話是不是一定最少五年? no, you can sell it any time you want. But because of the entry fee, exit fee involved, it's not worth it to sell it in too short a period.