For me the 3 biggest reasons for investing in crypto market in 2020, especially the top coins are:
1) Bitcoin halving event is coming in expectedly may.
2) Ethereum has also announced its improved Eth 2.0 version by mid this year.
3) Many countries are working on and coming up with pro crypto policies.
These events will have far lasting effects and i think that the last part of this year and next full year will be bullish so now is the best time to invest in top coins.