A separately managed account (SMA) is a professionally managed investment portfolio tailored to an individual investor's needs rather than pooled with others. Unlike mutual funds or ETFs, SMAs provide direct ownership of securities, offering more control over investment decisions and tax strategies. 

Originally created for institutional investors, SMAs have grown in popularity, with assets under management reaching nearly $2.2 trillion by 2023. 

Their key advantages include flexibility in strategy, greater tax efficiency, real-time transparency, and typically lower fees compared to actively managed mutual funds. Investors can customize holdings and optimize tax implications through strategies like tax-loss harvesting. 

Finsum: While SMAs can be cost-effective, additional fees from financial advisors may apply, impacting overall expenses.