In the 2017 bull market, Bitcoin would make crazy volatile bullish runs. During those runs, alts would consolidate and drop a little because all of the money was flowing into Bitcoin.

When Bitcoin stopped running, alt coins would start going crazy as traders cashed out & hopped back into those positions they exited before. Then as the price increases, more money flows into alt coins from Bitcoin instead of vice versa.

If you observe this cycle, it will make making money a lot easier. Right now, Bitcoin is consolidating as money flows into alt coins.