Crypto prices have been on a tear for the past several months, but the past week has been the clearest sign of a correction to climbing prices, though many see news of President Biden’s adjustment to the hikes on the capital gains tax as the most apparent reason for the market’s slide as investors cash out hoping their gains won’t be reached by a retroactive application of the rules.
In order to provide a methodology to detect bubbles in time series, Phillips, Wu, and Yu [23] proposed the supremum augmented Dickey-Fuller (SADF) test. This applies a series of right-tailed unit root tests to expanding windows of a time series (with a fixed start date), defined by where r2 is the final data point to be considered in each window, starting at r0 which is a fraction representing the smallest allowed window size and expanding to 1(the complete data set).

Savvy cryptocurrency users are therefore maniacally protective of their private keys, typically storing them in multiple digital locations — although generally not Internet-connected, for security purposes — and on paper or in other physical form.
Bitcoin is down roughly 20% week-over-week, around 30% from its all-time high of nearly $65,000 early last week. The market cap of the coin has dipped below $1 trillion. The tumble has been less severe for Ethereum, which hit an all-time high just yesterday but has since dropped 13% as the broader market has crawled back.