Hello,

I started with the API yesterday and went through the documentation. Very well documented with examples.

I have a few questions. The first three questions are motivated by desire to make the datafeed work as efficiently as possible while using as minimal resources as possible even though I have a 20Mbps ISP connection and a powerful desktop.

1. How many more messages would one generally receive for a typical equities symbol if one watched it with wSYMBOL as opposed to tSYMBOL assuming a Level1 subscription?

2. For trade messages in wSYMBOL and tSYMBOL when the Message Contents field has 'C' designation: do the bid and ask fields contain the best bid and best ask at the time of the trade?

3. On the average, how many bytes of data are fetch per tick from your servers? The protocol between my app and IQConnect is string based and seems to consume hundreds of bytes. I presume the connection between IQConnect and the servers is more efficient; can you give me an idea of the average number of bytes used per tick?

4. How many client apps can be simultaneously connected to IQConnect? I use a charting platform and besides that I would like to have my own app connect to the datafeed as well for purposes of additional processing and monitoring.

Thanks.

Hello,

1. Since the trade messages are filtered out at the IQFeed level, and not at the server level, only your internal bandwidth would be adjusted by this change. You would see a reduction in your inter-process communication by about 75%.

2. The bid and ask datafeed is not the same as the trades feed and so they can occasionally be a few milliseconds out of sync due to latency, but we always attach the best known bid and ask in our system to each trade at the time of the trade in our history.

3. I took a sample here and the quote I checked was 88 bytes. Little more or a little less depending upon symbol length and symbol precision.

4. You can only have one client app connected at any one time. Exchange regulations would require a second account to be purchased to view it in this manner.

Tim
Edited by DTN_Tim Walter on Feb 20, 2015 at 09:44 AM

Addendum to #4.

If you are asking about having all of those applications on the same PC though, that would be fine there is no physical limits on level one connections.

Tim

Perfect. Thank you Tim.

Just to clarify on #1.
So using 't' does nothing to limit bandwidth between the users server and IQFeed?

That is correct.

Tim

Why not have tSYMBOL be filtered at the server? It makes sense for following reasons:

1. It would make the datafeed much more efficient and robust to packet drops in the Internet. The fewer packets you send, the more robust the feed since you have fewer points of failure.

2. Every packet drop in the Internet leads to TCP misbehavior which adds to the delay.

3. It would reduce your costs by significantly reducing the bandwidth demand on your datacenter outgoing links (and the volume of quotes has been going up over the years with HFT while the volume of trades have remained the same).

4. As a retail trader, changes in quotes do not make sense to me. They are not actionable information to me since I am at a huge latency disadvantage compared to the hedge funds. I only care about actual trades.

This is something that has certainly been considered and is reviewed occasionally by our product management team to determine if there is enough interest to justify this enhancement. Unfortunately, the number of people that want to filter out the bids and asks is actually quite small compared to those that want it. So while everything you said is true, the demand has just not been there to date. But, we will continue to evaluate this as we move forward.

Tim