Depends on how you are trading. If you enter orders manually, you could easily get by with 10 MBPS. My cable internet connection averages 160 MBPS. Last week it went out and I switched to using my phone as a hot spot for an hour. The phone speed was only 12 MBPS, yet my system worked fine, even though I run NxCore which downloads, in real-time, every bid/ask tick and trade from both the NYSE and NASDAQ.
NxCore (which I have used for years) is a great product because they compress the data. However, you need more bandwidth if you want all the option data (>1.2 million symbols). A minimum of 500 Mbps and you still would likely be behind at times.
Because I also use other data vendors - there are times when I need > 1 GB.
Latency is less of an issue for me (30 ms). But I'm different than most of you.