I feel like some users do this sort of thing around leagues seasons start time (midnight PT or 3 am in my timezone), perhaps not as visibly or deliberately. So I decided to try to raise awareness about it by making it obvious and very visible, including by creating this market.
I've artificially manufactured almost M93k in fake leagues profits for this new Season 30 (Oct 2025). These are not real profits, I've not gained a single mana through these trades. By trading against my own (no alts, just my own account) limit orders (big and badly priced) placed shortly before the season start, the profit gets recorded when they got filled less than a minute later in the new season. But there must be an offsetting loss on the other leg of the trade, you say correctly, if I'm trading against myself? Well, the loss is carried by my old self at the time of the limit placement a few seconds before the season started, and due to the overlapping random closing season period the closing season has not yet ended, so the profit also gets accounted in that season fully offsetting the limit order losses meaning zero impact in the closing season. The key thing is that the profitable leg gets recorded for both seasons, but the losing one only applies to the old season.
Here's the market transaction log, showing 4x YES limit orders (2x for each of the two options) for M25k each at 99% placed in the last minute before season start, and two NO buys right after season start bringing both options back down to 2% (their original stable probability):
Here's my Trades tab showing the shares bought and sold, the probability swings, and the times bracketing the start of the season (I highlighted the "bad" limits in red and the "good" trades in green):
(note there are two more YES limits for M25k each at 99% for the "bitcoin drops back down" option not shown in the screenshot above since I'd have to page next to display them)
Here's my initial Season 30 (October) standing leading Masters by an absurd amount:
And here's the profit details popup pane when you click on my name there, showing that only the two winning NO trades are getting counted for this season:
I don't see any rule or prohibition in the guidelines against this, except possibly the vague "loophole" one:
Users don’t maliciously take advantage of ambiguity, loopholes, and technicalities, to benefit themselves.
The only "benefit" is the new season profits/ranking. If it ends up in a prized rank (top 10) by the end of the season, then that prize is the only mana benefit. There's no real 93k mana profit generated during the month, no infinite exploit, it's just a glitch from the quirky leagues season accounting. You can see my profile profits chart and confirm there's no 90k spike anywhere.
The execution is quite simple, here made big and blunt by fully swinging a small market, but could easily be done more subtly by spreading it over several markets without swinging them as much to avoid detection. It does involve some risk, as any trader (or maybe a lucky bot) could catch me within that midnight minute and steal the badly priced limit order, saddling me with the big loss. In case of several markets the risk would be minimized by having a bot or script execute all the trades within a few seconds around midnight.
All this to say, I don't think it's a huge issue if people do it a little, just not as extreme as I've done here. Where to draw the line, and how to detect and prevent abuse of it, are interesting considerations to keep the leagues games fun and fair.
Anyway, feel free to add more answers. I might bet on these since there's not much subjectivity. Apologies to fellow Masters for any rank disruption this may cause. I do hope (and hereby formally request) that my fake profits get reversed. Any comments or suggestions are appreciated, particularly from @mods or admins.
Update 2025-10-03 (PST) (AI summary of creator comment): - For the answer "I'll get punished (any fine, ban, or restriction) despite not breaking any rules or guidelines": it will resolve YES if I receive any fine, ban, or restriction by Nov 1, and NO otherwise. The "despite" clause is commentary and does not condition the resolution.
Update 2025-10-03 (PST) (AI summary of creator comment): - For the bug bounty answer: it resolves YES if any bounty payment was sent to me at any time before Nov 1; a later retraction does not negate that it happened.
Interpreting "by Nov 1" as event-based: outcomes are judged on whether they occurred before the deadline, not their later status.
1,000🏅 Top traders
| # | Name | Total profit |
|---|---|---|
| 1 | Ṁ219 | |
| 2 | Ṁ126 | |
| 3 | Ṁ96 | |
| 4 | Ṁ73 | |
| 5 | Ṁ51 |
People are also trading
@traders I'm expecting to resolve this NO as I don't see any need for a new rule explicitly forbidding it, for two pretty obvious reasons:
This specific loophole has been patched, so it makes no sense to forbid something that can no longer be exploited.
Even if it weren't patched (or someone tries holding limit walls through the random season end), no new rule is needed because it was was already covered. It seems the consensus from mods here is that it indeed violates the "loophole" guideline cited in the description, since despite not benefitting from direct mana gains from such trades, it potentially benefits the user (and to the detriment of others) upon ranking higher in leagues, and thus stealing someone else's league prize.
Now, I suppose admins can try again to manipulate it? Would be pretty silly though. Anyway, unless someone links to a public update of the guidelines where this is specifically mentioned (something like "can't trade against your own limits around league season start/end", I'll resolve NO when market closes in a week.
@deagol Somewhere in the 1-5% range seems reasonable. Remember there is a new Master of the Rules these days so Rewrite The Rules could be a first-month task and you never know, it could happen.
@traders I wonder if it's ok to resolve this? I assume very small chances the scheduler for next season open glitches again. Also, I don't think I'll be testing this same method then. I think I'll just check the timestamps of the trades counting for each season. But I hate to keep this option sitting there locking capital for a month, with basically zero information getting revealed until then. How do @mods feel about it?
@deagol I think it depends what you mean by technically patched. The code has been changed and it is demonstrated to be working since your league score went down. So that part is fixed. I would have resolved Yes.
@Eliza yeah, I'm not 100% sure how it all works to open and close seasons. This is what @ian said about the fix:
I just pushed a fix to the backend and scheduler.
So I'm guessing the backend fix took care of the current season's fake profits (thus allowing me to resolve the other option "Fake league profits reversed"), and the scheduler will do the same thing for next and all future seasons (fixing it permanently which is what I meant for this option).
If the scheduler uses the exact same code that was already used as a one-time patch on the backend, then I guess it's already tested and confirmed working as you said. My only doubt is, not knowing the precise details, I can't be sure if it's exactly the same code resource, or if it's a copy-paste of it on a different resource file and then edited somewhat, like, most likely it requires passing a variable or parameter for the real-time date-timestamp when it runs, which might have been hard-coded as a constant when it was run against the backend, or any number of other architectural details I'm not aware of.
In short, I know it worked as intended for this current season, but it seems the scheduler is a different thing which hasn't been tested in real time, and there may be a small chance (or zero chance) it glitches when it runs at the random time on Nov 1. That's why I made two options, one for reversing this instance, and another for the permanent "technical patch" which would run on its own at the start of every month. Does all that make sense?
In any case, that concern is likely an overabundance of caution on my part. Even if the scheduler glitches in Nov it'll definitely get re-patched right away, essentially making the exploit "impossible to reproduce" as long as someone's there to patch it now that they know how. So I would agree it can resolve YES.
NO holders ( @wolf and @Chumchulum ) any objections?
@deagol The precise details are available for you to view, the only change in the scheduler is to fetch both the start and end dates, not just the end dates (as you guessed):
https://github.com/manifoldmarkets/manifold/commit/6d797ff62d4373ff5b65f2661d5e434e377f14dc#diff-67827e30bdc3b0115d4e0676c74af523197cb5729cb222c2dec763a7741fae86
@Bayesian all the profit stuff looks only at "bets", not "fills". The "bet" of the limit order only has the original time on it. If that bet was before the period in question it would be filtered out.
@Quroe The fix is changing the start time of the league to the same time the previous one ended. There is no longer an "overlap period".
Someone could STILL try to do this same thing but they will have to leave their orders open indefinitely until the new league, etc. etc......and of course an adversary could come along and claim those orders at any point. It's risky!
I guess you guys all love drama and contesting stuff. These were all quite objective, straightforward questions and now everyone even mods and admins are lawyering, unresolving (looks bad on me), N/A'ing (which all hate), trampling all over my well defined market and common sense resolution. So, I won't touch this at least for a while, feel free to resolve as you all wish.
@deagol If you wanted to profit maliciously, you would have hidden it through mana laundering. You decided to publish your fake profits, offer to undo them with the limit order, and ask for a bounty to reward you (much less than you'd profit if you never announced this). Calling it malicious would set a bad precedent.
(much less than you'd profit if you never announced this)
Abusing this loophole does not generate any actual profit, FWIW. It is strictly a manipulation of league standings (among countless others that are trivial to come up with, and the only defense against them is that they are against the rules, and most people follow the rules, & the occasional few who don't are generally punished).
@Ziddletwix Is that what made it "fake" as opposed to real profit? I think I understand now
@deagol Ah, adding the bounty as a tradable option probably influenced the decision to give it to you.