According to Miles Deutscher, BTC dominance (BTC.d) must reverse by at least four percentage points and close below 60% to signal a shift in market structure favoring altcoins. Currently, BTC.d is rated as yellow with a score of 0.5, suggesting caution for traders considering altcoin positions. This key metric is closely watched, as a sustained drop below 60% could trigger increased capital flows into the broader crypto market, making it a crucial indicator for altcoin traders (Source: Miles Deutscher on Twitter, June 9, 2025).