0730 GMT - Bitcoin eases slightly after reaching its highest level since late January on Monday, driven by U.S. regulatory progress, stronger exchange-traded-fund inflows and a broad-based rally in risky assets. The pullback comes as oil prices rise following news that Iran-backed Houthi fighters are extending gains in Yemen to control the Red Sea, damping risk sentiment, although bitcoin remains above the key $85,000 level. Bitcoin falls 1.7% to $85,475 after rising to as high as $87,315 Monday, according to LSEG. "The move above $85,000 places attention on continued ETF inflows, corporate purchases, regulatory implementation and whether broader technology-market optimism survives higher interest rates," Zaye Capital Markets analyst Naeem Aslam says in a note.