Own an Index Fund? You're Making a Big Bet on Tech by Ian Salisbury It’s been a great decade for technology stocks. That means if you own an index fund, you could be making much bigger bet on the tech sector than you realize. It’s no secret the economy changed dramatically during the 2010s, as gadgets like smartphones and services like streaming TV took hold. Indeed, Netflix, which returned nearly 4,000%, was the decade’s top-performing stock.