Amazon is a mover and shaker in e-commerce and they have a pretty large 401(k) plan now. As of the end of 2018, their 401(k) plan has almost $6 billion in assets. So when Amazon ditches Vanguard funds for Fidelity as its recordkeeper for 2020, that is a big deal. Fidelity already has almost $2 trillion in plan assets under administration and handles plans for Facebook and Microsoft.