[oarsinsync]

> I don't think there are any successful quant strategies that don't rely on speed

There are plenty of successful quantitative algorithms that are in use by non HFT firms

> so basically anything with a proprietary API

If you’re not a direct market participant, colocated in the exchange, you’re not in a position to be talking about speed at all. Also most exchanges optimising for speed are not using FIX.

> is solely for amateurs

You’re not necessarily an amateur, you’re just leaving money on the table for someone else as you’ve not optimised that area of your trading infra yet.