Can anyone using a vendor API like Nanex, Polygon etc. comment on why you are using their APIs instead of just using a much cheaper feed from a broker like Alpaca, TD Ameritrade, Tradier etc. ?
Hey there, speaking for Nanex and NxCore only..... The difference between NxCore pricing and that of lower cost vendors is in the content of the data. Most other Internet-based market data vendors allow you to call a limited number of symbols. Even if you tried to call every symbol in each exchange from these other vendors, it would quickly exceed bandwidth and hardware limitations, because no other vendor has NxCore's compression. NxCore pushes *all* of the symbols in each exchange to you. If your end-user software has the capability, you can trade *every* symbol in each exchange using NxCore. NxCore is the only Internet based market data solution available that delivers this level of coverage. Subscribing to NxCore is like having a direct connection to the exchanges at a fraction of the cost.
Most brokers don't even have an API. IB's is by far the most comprehensive of any broker I have seen. Even TD's API looks rather sparse: https://developer.tdameritrade.com/apis I don't even see a way to place a trade via their API. Might as well use Google Finance's API for quotes and historical data.
a) Most brokers will restrict the number of simultaneous stocks symbols that you can monitor in realtime for free. For IB, the limit starts at 100 for most accounts. You have to pay extra for more symbols. b) My system monitors, in realtime, all NYSE and Nasdaq stocks. In the past I have tried Polygon, IQFeed and IB. On heavy days, at market open and market close, none of them could keep up with the quotes and fell behind by several seconds. Polygon was the worst, falling behind by more than 30 seconds on some days. I think Polygon made a fatal flaw using Json and Websockets. Easy to explain and to implement, but tough to get high throughput rates as compared to using regular TCP sockets and binary data. I have been using Nanex NxCore for years and even on the heaviest days it keeps up. I have even used NxCore during a power outage using my laptop with my cellphone as a hotspot, and it kept up at market open.
Customers experiencing high latencies through our WebSocket feeds are almost always not able to keep up with the amount of data being broadcasted. When clients are not able to handle the throughput fast enough, our server-side buffer fills (increasing latency) until the connection is eventually killed. We do not impose any limitations on the number of tickers you can subscribe to. We have clients taking down the entire market's quotes every day with no issue.
First of all thanks for responding. Great customer service. Okay, I will grant to you this. When I was using Polygon, it was with a 100 meg Internet connection. I have since moved my application to a hosted dedicated server with a 1 GB connection. I still have the code laying around, so if you give me a trial subscription a will be glad to retest and publish my findings on EliteTrader.