Polymarket's now got a market up on this.
https://polymarket.com/event/who-will-the-finding-satoshi-documentary-identify-as-satoshi

Note that the rules say:
"If multiple individuals are presented as equally likely in the conclusion of the documentary, the market will resolve to "Other". "

If the info @Dssc offered below is good that it's an equal Hal+Len effort, then maybe there's money to be made betting on that?

I'm definitely past kelly by now, so some information I've been quiet about:

Bram Kanstein, a bitcoin youtuber, claims to have seen a preview of the documentary.

How reliable is this? Well, I don't really know why he would lie about this, especially when he is actively praising and promoting the documentary. It also would make sense, as in an interview, Tucker Tooley, the producer of the documentary, has said that they have shown it to various influencers.

Assuming that he has seen the preview, he has given some pretty big hints about who the documentary will name:

"It's not Adam Back and definitely not Craig Wright" is pretty explicit. He even calls it a spoiler himself!

This isn't explicitly referring to the documentary, BUT:

1. It's wedged right between two posts explicitly promoting the documentary

2. Bram clearly views the documentary positively and claims that it has a "really compelling case," implying that he agrees with the conclusion of the documentary. It seems extremely likely that any opinion he has about whether Satoshi is a single person or a duo would come directly from the documentary

3. As far as I can tell, he rarely posts about Satoshi, and has only done so recently in reference to the documentary.

He also replied to this under the Satoshi = Duo post. This isn't super strong evidence, but it does stand out, as he didn't reply to any of the other theories under this post, such as ones suggesting Roger Wilco or John Nash.

He also replied to this, with a very suspicious "What if they can't." I think this strongly implies that the documentary will name a dead duo as Satoshi, as it is the main reason why somebody would be unable to sign with the "Satoshi private keys."

Then there's this "almost" from Bram from a post suggesting that Hal Finney is Satoshi. Combined with the earlier duo post, I interpret this as suggesting that it is a duo involving Hal Finney. It wouldn't make sense to reply "almost" to an answer that is just the wrong person, but it makes perfect sense if it's half-right if the documentary states that Satoshi is half-Finney.

There are also some comments to people saying that they don't want Satoshi to be found with "I think you will like the conclusion." This seems like it implies that the documentary will actually go with no answer, except...

He above seems to be confident that the he now knows who Satoshi is, and explicitly states that the documentary answers the mystery here. Instead, I think these "you will likely the conclusion" posts are rather addressing the worry that a revealed Satoshi will tank the price of Bitcoin due to Satoshi's stash. This probably means that the documentary's suspects will be already dead, rather than just no answer.

Finally, there are two posts implying that, while Satoshi was very much "in the PGP corner," Adam Back is "still WRONG." This is interesting, as Hal Finney and Len Sassaman are the two candidates most closely related to PGP, as they both worked together developing PGP.

In aggregate with the previous evidence, I think this clearly points towards a Hal Finney + Len Sassaman duo. They both fit the earlier "6 pillars" teaser from the official account. The main counterpoint against Len Sassaman was the documentary's focus on the US timezone, while Len was in Belgium at the time. However, a duo with somebody in a US timezone doing the Satoshi posts would be an easy explanation for the documentary. The main counterpoint against Hal Finney was the documentary having the image of Hal Finney running a marathon while Satoshi was posting. However, a duo with somebody else posting that one time would be an easy explanation for the documentary as well. Furthermore, both Hal Finney and Len Sassaman stand out as the only candidates with a costly shot in an entirely different location. While both the Sonoran Desert shot and the Brussels shot could just be investigating a candidate they didn't end up choosing, having to go to a new location is costly, so it seems likely that they would only reserve this for their actual final candidates.

@Dssc I did a longer write-up of why Len Sassaman alone was not Satoshi:
https://medium.com/p/935f95695bd9

That's possibly irrelevant to this market, as it's quite possible that a Coinbase sponsored documentary is going to present a fan favorite theory like Len or Hal, or Len+Hal, as you suggest.

I think the divergence between this and Ben Shindel's market (which is currently favoring Todd, Back, Szabo, other) is interesting, and Ben's market odds are probably much closer to the reality of who Satoshi is.

While it's easy to disprove Hal Finney alone as Satoshi and Len Sassaman alone as Satoshi, I guess it gets more complicated when you have to prove that they're not working together. Maybe I'll take a shot at that, if the movie comes out with that conclusion, but I'm not gonna make the effort until I see people jumping on that idea.

@DerekWangZO6N I don't think this answer is valid because it's a dependent market/sum-to-one, and it's superset of the other answers (except for "Movie does not give an answer"). "Movie does not give an answer" only works because it's disjoint from any person being named.

@Dssc Yeah, I thought it was just a troll post. I'm fine with trolling, keep them coming if you want, but they will all resolve to zero.

@PeterMillerc030 I doubt it was intentional, I think it's easy to confuse dependent market mechanics vs. non-dependent market mechanics.

@nsokolsky Interesting theory. I think he was the 3rd Bitcoin miner:
https://blog.dustintrammell.com/block-286-and-satoshis-coins/

Could that be Satoshi joining his own network to get more activity because no one else but Satoshi and Hal had joined?

Dustin Trammell does double space after a period, and he does it perfectly, just like Satoshi. Here's people on the cryptography list who double space, and how consistent they are:
(format is "number of lines posted / number of times they did a single space instead of double")

Adam Back: 9343 / 10
Ray Dillinger: 10430 / 60
James A. Donald: 15521 / 56
Hal Finney: 6502 / 125
John Gilmore: 8426 / 84
Ian Grigg: 25304 / 96
Travis Hassloch: 25342 / 159
Robert A. Hettinga: 142696 / 4531
Dan Kaminsky: 1288 / 2
John Kelsey: 5927 / 2
Ben Laurie: 12223 / 219
Satoshi Nakamoto: 686 / 0
Dustin D. Trammell: 315 / 0
David A. Wagner: 2982 / 0
Zooko: 6150 / 26

@PeterMillerc030 added David A. Wagner

@PeterMillerc030 Dustin Tramell comes from feeding the output file of this GitHub to Opus and asking it to find candidates not yet mentioned: https://github.com/basvandorst/where-is-satoshi

I’m curious if the poll options will cover every person the documentary will mention as a potential candidate.

Claude/Opus research updated on all the comments in this thread, now it believes the probabilities are as follows -- with the confidence interval included in brackets

Len Sassaman: 48% (35-62%)

Hal Finney: 18% (8-28%)

Other / unlisted: 8% (3-14%)

Sassaman+Finney collab: 6% (2-12%)

Dan Kaminsky: 5% (2-10%)

Nick Szabo: 3% (1-7%)

James A. Donald: 3% (1-7%)

Adam Back: 2% (0.5-5%)

Movie does not give an answer: 2% (0.5-4%)

Wei Dai: 2% (0.5-4%)

Meredith Patterson: 1% (0.2-3%)

Dave Kleiman: 1% (0.2-2%)

Full analysis here: https://claude.ai/public/artifacts/d2ffd808-b929-4646-9da3-f9b36ac35ce4

Disclaimer: I am not endorsing Claude's answer, just experimenting to see how good Opus Research is at predictions.

@nsokolsky FWIW, I added Meredith because she's a C++ programmer and Len Sassaman was not. If it's him, it could have been a collaboration. If he's Satoshi, he either lied like crazy to his wife such that she doesn't know, or she lied like crazy about him not being Satoshi. If the film really does go the route of naming Len, it seems possible they'd name both.

@PeterMillerc030 watch party on the 22nd? Just you, me, and the other 111 people who bet on the market.

Think how much mana you can earn for the low price of $14.99

Added another answer. Please don't sue me CSW! 🥀🙏🏻😂

Still surprised Sassaman is so high here. Have y'all read what he thinks about Bitcoin?
https://x.com/search?q=from%3Alensassaman%20bitcoin&src=typed_query

@PeterMillerc030 I was trying to think of unlikely answers which would still fit the criteria described by claude and by the preview.

The preview implied there was some connection to Bram Cohen and other people suggested that maybe the film concluded that Satoshi was dead.

Len Sassaman is one obvious choice, but I don't think Len is Satoshi (it would take a while to explain why, maybe I'll try later). The simplest reason is just that Satoshi posted after Len died.

The director also states that, "the answer is one that some may not have considered". Sassaman is pretty high on the list of usual suspects, not a particularly obscure choice.

Dan Kaminsky was friends with both Cohen and Sassaman. He died in 2021.

Dan was a security expert. He liked to mock journalists who searched for Satoshi, calling Satoshi their white whale.

Len Sassaman is famous for having an obituary in the Bitcoin blockchain. Dan Kaminsky is the guy who programmed that obituary into the blockchain. I noticed that the obituary has double spaces. Dan Kaminsky liked to double space after a period, just like Satoshi famously did.

https://manifold.markets/Dssc/will-the-upcoming-documentary-findi?r=RHNzYw
If anybody wants to also bet on whether the documentary will actually find him this time

If they claim it's multiple people, is that "Other?"

@ChurlishGambit If they claim Satoshi was multiple people that are on the list, then it resolves equally to each of those people.

If they list multiple people and one or more is not on the list, then "Other" gains the weight of those unlisted people.

If they claim it was a specific group, which is not listed here, i.e. "Bitcoin was made by the CIA", then it resolves to "Other"

If they claim it was multiple people, but do not name any specific people or any specific group, then it resolves to "Movie does not give an answer".

@PeterMillerc030 Thorough! Thanks

I have no idea what the documentary will go with, but I wrote up a few more thoughts for why I don't think it's actually Hal Finney:
https://medium.com/@tgof137/hal-finney-is-probably-not-satoshi-bf91a23bb151

Why I think the documentary will say Hal Finney:

The Official Finding Satoshi Documentary Twitter Account has posted numerous teasers besides the video about the documentary, including:

These basically completely fit Hal Finney being who the documentary is going with. US geographic profiling, major Extropian, not british, double spaces after periods, PGP/Remailer Dev, including working at PGP Corporation directly under Phil Zimmermann, an interviewee. The other candidates only fit like half these descriptions, with the exception of Nick Szabo. (Although Nick Szabo isn't really as well known as Finney for having Extropian and PGP ties, and doesn't have teaser footage)

Also, at 1:43 in the trailer, that's Sonoran Desert, based on the cacti, which is where Hal Finney was crypreserved. AFAIK Hal Finney is the only candidate with any connection to the Sonoran Desert.

Also, the official website has this quote, which implies that there is a reveal, and it's going to be a single person. The website and other promotional materials generally have a general messaging that this is supposed to be a celebration of Satoshi rather than a doxxing of a person ("part human portrait"). This is purely speculation, but it reads more like a description of a dead person rather than a biopic of an alive person who doesn't actually want to be in said biopic IMO. Would be much easier to have a "human portrait" storytelling arc of a guy who isn't alive to contradict any details.

I saw the photo of Hal Finney in that race, but it seems to be early in the investigation when they are still introducing the candidates. My expectations for the documentary aren't super high, but I do expect them to at least aknowledge some of the counter-arguments for whoever their candidate ends up being, such as the race. It could also easily just be a red herring to make their eventual reveal more of a plot-twist.

@Dssc Szabo's picture is on the whiteboard in the trailer.

Also, at 0:19 in this video
https://x.com/findingsatoshi_/status/2041883638825107922

I assume the Len Sassaman bets are based on the image of Brussels in the trailer. However, I think that's actually because, according to their website, they are interviewing Meredith Patterson, who I believe lives in Brussels, and who, among many other things, is also the widow of Len Sassaman. I think this is actually somewhat evidence against Sassaman being the documentary's candidate, as she has publically denied Len Sassaman being Satoshi in the past, and is likely to have the same stance in this interview. This certainly doesn't prove anything, but I do think it makes the Brussels evidence a lot weaker.

Why I think it's probably not Hal Finney:

Jameson Lopp wrote an article where he found that Hal was running a race at the same time that Satoshi was writing an e-mail and sending a bitcoin:
https://blog.lopp.net/hal-finney-was-not-satoshi-nakamoto/

At 1:54 in the preview, their whiteboard has a photo of Hal Finney in that race.
https://www.youtube.com/watch?v=gVxAwomug08&t=1s