Huge gains recently. Is my strategy a good idea?

So as the title said I've had about a 34% increase in my directly managed day-trading funds. I'm super new to this so just trying to diversify as best I can. My strategy has been to sort of delve into markets I know are growing and invest in the base companies. I.e. instead of just investing in a random solar company I instead invest in the company that makes all the inverters for solar panels across the board. This has obviously served me really well thus far but I am worried that my luck will