Bitcoin in US dollars (BTCUSD) has been trading since June 2017 and has shown that it can be a leading indicator at significant tops and bottoms for the US stock market.
The daily BTCUSD and S&P 500 (SPX) chart courtesy of Trading View illustrates their relationship.
In December 2017 BTCUSD reached its bull market high about a month and a half before the SPX.
BTCUSD then went into a nearly one-year bear market bottoming ten calendar days before the SPX completed an intermediate size correction that concluded in late 2018.
In February 2020 BTCUSD failed to match the SPX in making a new bull market high. Its secondary peak came six calendar days before the SPX top.
In the subsequent crash that occurred in several markets, BTCUSD bottomed ten calendars days before the SPX. When the SPX did bottom, BTCUSD secondary bottom was considerably above its crash lows. A case can be made that BTCUSD is more speculative than stocks, its secondary bottom was strong evidence of a subsiding panic.
As of February 12, 2021, both BTCUSD and SPX were making new bull market highs. If BTCUSD continues its relationship, SPX could make a new high one week to a month and a half after BTCUSD makes its bull market climax.
Watch BTCUSD, it could provide evidence for a significant US stock market top.