The bigger hit will be all their star quants going full solo (supervised with Claude).
What is Jane Street doing these days? Still HFT MM?
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Fuck, ocaml's never getting row polymorphism now, my day is ruined.
Jane Street doesn't care about this loss. But it is almost always the effective altruists accelerating their own downfall.
And yes, Anthropic included.
And they're still making tens of billions this year. Whatever they're paying in taxes, it isn't enough.
Original headline is "Jane Street suffers $15bn loss in July market ructions".
HN guidelines do request use of original title and in this specific case the change of title is misleading by implying that situational awareness directly caused losses at JS.
In the text it says "the US trading firm was wrongfooted during last month’s market ructions including the meltdown at AI-focused hedge fund Situational Awareness" so while SA is mentioned the implications of a direct link to the losses is less strong.
If SA's losses were around $30B does that mean Jane Street owned half?
All the article really says is that JS lost money in July.
The title has been editorialised (original headline didn't mention SA). The text just mentions the July market ructions included SA losses.
It's all so sketchy. Jane Street were investors in SA but presumably were much more sophisticated and savvy than Leopold. When SA got in trouble, 3 firms got into a bid war for the assets at fire sale prices: Citadel, Jane Street and a third I forgot. Citadel outbid the other 2, but it's all weird, like Jane Street wanted in on the popular boy's book that they knew was going to tank and just were waiting around in the water like sharks.
> like Jane Street wanted in on the popular boy's book that they knew was going to tank
This is completely illogical. If they knew it was going to tank, they wouldn’t invest.
As conspiracy theories go, this one doesn ’t even have a leg to stand on.
Nothing about any of that is sketchy. It’s in their mutual interest to avoid a fire sale.
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Who the heck is Jane Street? Oh, I see, they're a "quantitative trading firm", whatever that means.
AFAIK they’re like a hedge fund with quants that trades its own money. In fact, most people (everyone?) who works there is a quant. It’s the only way they trade. They are extremely profitable. Of course you can Google this and get a more accurate picture. I know them as the most famous OCaml shop.
Personally I have mixed feelings about what they do. The engineer in me used to root for them. The way they operate as a pure tech shop was very refreshing in the hedge fund/traditional finance world (crypto world is the opposite). But the trader in me now abhors how they make their money, that is arguably at the expense of retail traders.
They trade stocks quickly with computers.
And quants!
“By our calculations, Jane Street ponied up a one-off $200mn to do the deal and then locked in a further $200mn of costs per annum, at least in part, to avoid us gawping at their numbers every quarter. Wowsers” [1].
[1] https://www.ft.com/content/28a51284-98cc-4767-a306-0540d2656...
> Jane Street has generated more than USD 40 000 000 000 in net trading revenues in the year to Friday, even accounting for the July loss, which exceeds its entire haul for 2025, according to one of the people familiar with the matter.
Sure. It’s still an embarrassing hit they’d want to keep secret, particularly if they’re still in those positions. Paying hundreds of millions to hide a $15bn MtM loss makes sense.
They're still up $25B for the year, so it's hard to feel bad for them :-)
On a more serious note, Jane Street has hired some very impressive technical talent. I'd work for them, myself, if I didn't have to relocate to Chicago.
Their nerd sniping is top notch. I almost accidentally applied for a job with them.
I don't think they even have a Chicago office. They're based in New York.
> I'd work for them, myself, if I didn't have to relocate to Chicago
Right, yes, exactly. Same here. Not wanting to relocate to Chicago is the reason that you and I both do not work for Jane Street.
Knock it off. These sorts of responses are uncalled for. Please review the HN Guidelines.
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Archive link (https://archive.is/20260814213548/https://www.ft.com/content...)
Pretty short so I imagine more details and analysis are forthcoming.
Really weird writing and grammar errors. Odd
https://youtu.be/rE75WvOtcu8 This video from Patrick boyle has a lot of detail.
Always been a bit wary of Patrick. He reminds me of those people who in the 1990s/2000s would have become professional talking head guests on CNN. The older ex-academic/ex-industry guys who knew how to spin popular news stories into sound bites for the general public, while offering a veneer of authority. I'd rather get analysis from people who don't chase pop news stories for a living.
That leaves basically nobody.
100%
agree
He's offering entertainment not investing advice.
But he is very entertaining and has more than a veneer of authority. His early educational YouTube videos covering topics like derivatives pricing are genuinely very good.
Tragic
Explain