It is applicable for investment in stocks and mutual funds, and I assume that it may have some impact on the cryptocurrency market as well. People usually sell some of their stocks in March, since it is the last month of the financial year. They do this in order to keep capital gains low for the next year. In a few cases, investors book losses on some of their investments in order to keep the capital gains low. In many of the countries gains from Bitcoin trading is regarded as capital gains and therefore this may be applicable in the Bitcoin sector as well.