A subset of an exchange-traded fund (ETF) that is representative of the shares comprising the fund. ETFs shares are redeemed or issued through creation units. In other words, a creation unit constitutes a large block of shares of an ETF or other unit investment trust (UIT) which are sold to institutional investors. Creation units can be exchanged with the issuer for a specific amount of ETF shares. For example, a fund’s creation unit might be 30,000 shares. That means an investor could buy 30,000 individual shares of the ETF and trade them for the underlying assets. Alternatively, the investor could buy a creation unit’s worth of underlying assets and receive ETF shares instead. Effectively, creation units help keep the price of ETF shares near their net asset value (NAV).