16 comments

  • int32_64 2 minutes ago
    Ever since the infamous work of some of their alumni I have wondered what the culture of JS is actually like.
  • fancyfredbot 35 minutes ago
    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.

  • otterley 1 hour ago
    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.

    • Lerc 15 minutes ago
      Their nerd sniping is top notch. I almost accidentally applied for a job with them.
    • bmitc 12 minutes ago
      I don't think they even have a Chicago office, so it's good you didn't relocate there. They're based in New York.

      https://www.janestreet.com/culture/our-offices/

    • margalabargala 34 minutes ago
      > 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.

      • otterley 21 minutes ago
        Knock it off. These sorts of responses are uncalled for. Please review the HN Guidelines.
  • tolugenius 1 hour ago
    Archive link (https://archive.is/20260814213548/https://www.ft.com/content...)

    Pretty short so I imagine more details and analysis are forthcoming.

    • totetsu 1 hour ago
      https://youtu.be/rE75WvOtcu8 This video from Patrick boyle has a lot of detail.
      • dmix 51 minutes ago
        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.
        • mitthrowaway2 6 minutes ago
          Is there anything he's said in particular that, given the benefit of hindsight, you feel has turned out to be misleading in retrospect?

          Speaking for myself only, but if I were going to post a comment like yours on a public forum insinuating doubts about a specific person and vaguely implying their analysis is not trustworthy, I'd come armed with at least once example.

        • fancyfredbot 28 minutes ago
          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.

          • dmix 11 minutes ago
            > His early educational YouTube videos covering topics like derivatives pricing are genuinely very good.

            Which is a common story these days. Nothing wrong with that, there are worse people who become the Youtube-content guy. I've just gone down that road enough times to know to eject early.

        • inigyou 32 minutes ago
          That leaves basically nobody.
          • dmix 6 minutes ago
            This isn't the TV news era. If you're into learning science you're not limited to choosing between the Michio Kaku or Neil deGrasse Tyson types. Same with finance and economics or any other topic.
        • bb-connor 30 minutes ago
          100%
        • thechairman12 38 minutes ago
          agree
    • redwood 1 hour ago
      Really weird writing and grammar errors. Odd
  • wmf 22 minutes ago
    If SA's losses were around $30B does that mean Jane Street owned half?
    • fancyfredbot 13 minutes ago
      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.

  • JumpCrisscross 1 hour ago
    “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...

    • jt2190 1 hour ago
      > 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.
      • JumpCrisscross 45 minutes ago
        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.
  • lz400 1 hour ago
    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.
    • JumpCrisscross 48 minutes ago
      Nothing about any of that is sketchy. It’s in their mutual interest to avoid a fire sale.
      • lz400 8 minutes ago
        It’s sketchy to invest in a fund they probably knew full well had terrible risk practices and was likely going under on the first drawdown.

        When Leopold went to pitch NY investors they all passed and thought he was full of it. He could only convince California tech guys. Savvy finance guys saw SA for what it was (leveraged beta trade). Jane street are finance guys, not California tech bros.

    • Aurornis 46 minutes ago
      > 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.

      • lz400 10 minutes ago
        One theory (I don’t necessarily believe it): Jane Street was after the private part of SA’s portfolio (Anthropic), which is difficult to come by. Losing a few million dollars investing and getting in that network was worth it for them to try to groom Leopold to eventually sell them the private stake
    • EdwardDiego 50 minutes ago
      [dead]
  • choult 1 hour ago
  • naveen99 53 minutes ago
    The bigger hit will be all their star quants going full solo (supervised with Claude).
  • brcmthrowaway 13 minutes ago
    What is Jane Street doing these days? Still HFT MM?
    • mattlamz 8 minutes ago
      A little bit of everything
  • giraffe_lady 26 minutes ago
    Fuck, ocaml's never getting row polymorphism now, my day is ruined.
  • Taikhoom10 1 hour ago
    [dead]
  • camel_gopher 1 hour ago
    Tragic
  • rvz 42 minutes ago
    Jane Street doesn't care about this loss. But it is almost always the effective altruists accelerating their own downfall.

    And yes, Anthropic included.

  • xhevahir 55 minutes ago
    And they're still making tens of billions this year. Whatever they're paying in taxes, it isn't enough.
  • deweywsu 26 minutes ago
    Who the heck is Jane Street? Oh, I see, they're a "quantitative trading firm", whatever that means.
    • ahartmetz 22 minutes ago
      They trade stocks quickly with computers.
    • sheepscreek 15 minutes ago
      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.

    • fragmede 4 minutes ago
      What's the grumpy version of xkcd 1053? Anyway, Jane Street does high frequency trading on Wall Street, and they're kind of a big deal in that sector. They date back to 1999, with some IBM people. Other than the money, the reason they're interesting for HN is they're an OCaml shop and do a lot for that ecosystem. So if you're a computer language nerd and want to work in a functional programming language, but one that has real world applications, and make a lot of money doing it, Jane Street is the place to be!