What particular year of the month of March are you alluding to that Bitcoin had suffered dump? Is it March of every year? If that's what you mean then it's not correct because March of 2020 Bitcoin was already in a downward slope before then. Except you're harbouring an element of superstition, otherwise there's nothing spectacularly doomsday about March. You can talk of December and that would make a much clearer prediction as investors are worth to take profit every December for festive activities thereby causing the market to slump.
I am not right if commented it happens every March, but what I meant was that it happened in 2019 and also in 2020 that will it continue like that. You are not right commenting that bitcoin was already in downtrend in February 2020, bitcoin increased to $10500 in the bull trend of January and February of 2020, while it decrease back as usual to a price above $8000 until middle to ending of March 2020 when it decrease below $3700, March was the worst month for bitcoin in 2020, while also March was the worst month for bitcoin in 2019 as it decreased also below $3800 in March 2019. As for other years, I am not certain or something of such did not happen, but what I meant is that as it happened two times in two years, hope not going to happen this year.