What to invest next?

Nothing to invest on

Gold had been the best option for investment, but it is no longer the case because The financial market raised its price too much. The stock market has been stagnant and possibly in a bubble state. Government bonds are likely to be in the bubble because the whole economy is generally based on low-interest rates. Government bonds and Treasury might be the last hope for most investors to make enough profit safely. 

Waiting might be the answer.

Theoretically, I have no idea what to do at the moment.

If you are an aggressive investor, the possible solution would be investing in Bitcoin extremely defensively or taking a short position in the Japanese stock market or buying an inverse ETF on the Stock market. It, however, might be the best option to wait for the next opportunity, such as the following depression, as Warren Buffett would do.