Changes in institutional investors' interest in altcoins significantly impact the market. Rising interest drives capital inflows, pushing prices up, boosting confidence, and attracting retail investors, creating short-term booms. However, due to altcoins' high speculation and low liquidity, institutional funds focus on major coins like Bitcoin and Ethereum, leaving altcoins with limited long-term support. Waning interest can trigger sharp sell-offs, amplifying volatility. Data shows that when Bitcoin dominance rises, altcoins often face selling pressure. Moreover, institutions favor compliance and stability, while altcoins’ weak tech and regulatory gaps reduce their appeal. In early 2025, institutional capital via ETFs has strengthened Bitcoin’s position, extending its dominance cycle and shrinking altcoin season windows. Thus, shifts in institutional interest not only drive prices but also reshape market dynamics, influencing capital flows and investor sentiment.