(Bloomberg) — Owners of Invesco Ltd.’s famed tech fund QQQ (QQQ) voted to convert the product into an open-ended structure, a move that could unlock hundreds of millions in annual revenue for the asset manager. Shareholders of the $402 billion Invesco QQQ Trust Series 1 approved changing the fund’s structure from a unit investment trust, which is a little-used structure dating back to the birth of the first exchange-traded funds in the 1990s, an Invesco spokesperson said Friday. Most Read from Bloomberg ...