You need to balance your investment growth target against the inherent risk that you’re prepared to subject yourself to.
At the most risky end of the scale, you could place a bet. If you can find a bet that offers odds of Evans (1/1) then (if successful) you would have doubled your money. However, there is a very real risk that you will lose all your money!
Another option is to invest in shares. However, to double your investment in just a month, you would either have to be very lucky or very confident that the company you are investing in is both undervalued and is about to become very popular. Again you risk losing some or all of your money.
My advice would be to look at a longer horizon to achieve your aim of doubling your investment. Research and buy into quality shares. Look at the track record of the management and their record of delivering excellent profits and dividends. Try to assess whether the share price is undervalued. (There are lots of free sources on the Internet that can help you determine how to assess shares).
You could ask to have your dividends reinvested into buying more shares, which will help accelerate your rate of capital growth. Don’t allow short term market blips to panic you into selling.
By utilising this approach, it is possible to double your investments. One company that I have shares with have gone from 10 to over 20. This has been achieved over 8 years. I am delighted with this investment, and I have also benefitted from dividends throughout these years.