On Wednesday, BTC dropped below $8,000 and traded around $7,500, losing most of the gains it made from mid-April to early May. With Wednesday's plunge, BTC is now down 41 percent this year. Lee believes the drop is only due to typical crypto volatility, and explains his bullish stance with three major factors.
Read more https://cointelegraph.com/news/tom-lee-holds-to-25000-bitcoin-price-prediction-cites-three-supporting-factors
Tom Lee probably actively uses the index and predicts. Therefore there is interest both in the index and in cryptocurrency. And if to watch a volatility picture historically, then it is possible to see the next growth. In general he has good forecasts, especially that in 4 years cost will be $125 000.