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Comment by dharmab | Hacker News Reader

One of Starlink's planned markets is global high frequency trading. The latency of radio and laser transmission in atmosphere and space is much lower than undersea fiber optic cables. (Light moves significantly slower through glass than through air.) Even with the longer distance and retransmission they stand a good chance of being lower latency across oceans than undersea cables.

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I originally though this would be a good market, and have voiced that opinion on HN, but afaik SpaceX has never said anything about it.

Someone has since pointed out to me that HFT is currently done by bouncing microwaves off the atmosphere. This, unlike fiber, should be faster than SpaceX's constellation making that business unlikely to work out. (Possibly unless high bandwidth almost as low latency is useful).

> Someone has since pointed out to me that HFT is currently done by bouncing microwaves off the atmosphere.

I would love to read up on this. Is this similar to HARP?

Bouncing waves off the ionosphere has different ranges depending on the time of day. Do you have more info on how that's currently used? I'm curious to learn more.

Not really, sorry

This is not true as far as I can tell. HFT does not appear to be part of spacex’s strategy at all.

Specially now that the satellites have no crosslinks.

My understanding was that was just a limitation on the first batch, as they're still developing the design, but they're intending to cross link in future. Is that not the case?

Sure, but that's significant feature. Other satellites will be built and launched by the time they get there, and they absolutely need to OSL for capacity.

I did the math on this. It probably wouldn't be good for hft. The highly profitable hft is done on the floor of the nyse. There's some from Boston but they typically use directed radio instead of fiber-optic. Satellites will be even slower, but maybe cheaper if you're sending date from California or Australia. But it's still probably cheaper (and more profitable) to put a machine on the floor or even just in NYC.

I'm not sure why hft would be a major pitch. These people fight for floor space at the nyse because that much latency matters.

Think London to NYC, or NYC to Tokyo. Fiber will be slower. https://youtu.be/QEIUdMiColU?t=196

What I'm saying is that it's faster to just buy a server in NYC.

The idea is you profit on acting on cross market trading before anytime else can. It's not about latency to any single market.

Seeing something before someone else can IS latency. That's why servers on the NYSE floor (or ANY SE floor) are really expensive. Because it gives you an advantage. It isn't humans reacting and buying in HFT, it is computers. The humans are constantly updating algorithms, but HFT means it is the computers doing the reactions (based on algos written).

They have servers in both locations. If you see that a stock starts falling in London you have a time window where you can still sell it at a higher price in say New York, until the price drops to the same level thus closing the opportunity for arbitrage.

How quickly can you "see" the price falling in London and get that message to NYC? Whoever "sees" it first wins, right? That's what they're talking about.

I don't think you understand what many HFT firms do. They arbitrage between exchanges. For example the option or futures price of a security in Chicago and price of the underlying in New York. Also arbitraging between equities listed on multiple exchanges.

Co-location isn't a solution to these problems, and low latency lines between exchanges in different parts of the country and world is a huge huge factor to successfully implementing many/most HFT strategies.

GP is obviously not talking about HFT on the NYT, but HF arbitrage between different global exchanges.

s/nyse/arbitrary exchange/g

It seems useful, but tricky to monetize. But if you gave priority to hft traffic then you could charge more as it would still have a small advantage over a standard StarLink plan.

How would that be hard to monetize? You literally just charge people for internet access.

* HFT firms will pay for it if the latency is lower

* Online gamers that play with other people around the globe would also probably be willing to pay to get their ping down.

* Maybe they could have a LEO CDN.

* People like me who travel a lot would be willing to pay for it. It would be especially sweet if I could somehow ditch my phone plan and just have global satellite coverage and use VOIP via Google Voice or something.

Because HFT firms can pay for a standard StarLink and get the same results. There are few HFT customers and you have to offer them something that can't get from your consumer service if you want them to pay commensurate to the value provided.

Your other points have nothing to do with my HFT specific comment.

It's very likely that standard Starlink plans will downlink traffic as close to the customer as possible to reduce lateral utilization, but HFT needs to route traffic on the constellation all the way across the Atlantic.

It will have to be something like this that gives best possible latency for a higher price.

"standard StarLink"?

StarLink doesn't exist yet, and when it does, it doesn't seem unreasonable to think that two satellite constellation providers could serve the HFT market and both be profitable.

They could just charge extra for the “last ms”. So add a ms of latency for the standard plan, and remove it for the HFT plan.

Still totally missing the point. You have to offer something extra to the HFT traders to sell them a $10000/month plan instead of a $49.99 plan. Discriminate on latency somehow for their traffic. Prioritize packets, prefer shortest links over most expedient links, minimize hops. Otherwise if they will just buy your standard plan and you don't monetize them effectively.

Where did you get the idea that satellite constellation internet will cost $10000/m? Or that HFT firms aren't already paying much more than $49/m?

... They're just numbers picked out of the air for one last illustrative attempt to explain why you need something special to entice HFTs to pony up way more than a standard internet plan so you can monetize them effectively.

The point is that HFTs aren't going to be ponying up "way more"...

It's going to be a bit more, for a bit better latency.

Your comments are predicated on the assumption that this internet service is going to be significantly more expensive than existing fiber subscriptions, and therefore needs many benefits to outweigh the increased cost. But I have seen no reason to believe that this will be the case. Every statement I've seen indicates that these services will be quite competitive on price.

No, you've still completely missed the point. I give up.

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