Two Bugs We've Found In MANTIS
We’ve found two bugs in MANTIS. Both are fixed in development and will land in the next update, but neither fix is shipped yet — so this is a heads-up rather than a release note.
We’d rather tell you about them while they’re still live than mention them quietly afterwards. The second one has a workaround you can use today, and it’s the one more likely to affect you.
1. The daily cycle marks
What it does
In certain conditions MANTIS marks a daily cycle low that is higher than it should be, when a deeper, equally valid low sits in the same dip.
The detector accepts a daily low once price closes back above its 10-day moving average, within a fixed number of sessions of that low. On a slow recovery, a dip can produce two valid candidates — and the deeper one, being earlier, can run out of sessions before the recovery arrives. The shallower one is still inside its window when price finally closes back above the line, so it gets confirmed and the deeper one is discarded.
The same single recovery validates one and rejects the other, purely on timing.
A live example
COIN, this month. Two valid lows sat in the same unbroken dip below the moving average:
- 31 July — $139.11
- 6 August — $145.14
Price closed back above the average on 13 August. That’s one event, ending one dip. But it fell within the confirmation window of the 6 August low and outside the window of the 31 July one, so MANTIS marked $145.14 and dropped a low six dollars deeper.
What it affects — and what it doesn’t
Affected: the daily cycle low marks shown on the chart, and the daily cycle read-out in the indicator panel — the day count and the last daily low.
Not affected, mechanically: weekly cycle lows, the weekly projections and timing windows, the four-year cycle work, and the Accumulatoor deployment triggers. Those are computed from the weekly lows and a separate test, and never read the daily marks. No other number in the app is wrong because of this.
But that’s a statement about plumbing, not about importance. The daily cycle isn’t a side feature bolted onto the weekly one — a weekly cycle is roughly three daily cycles, and the daily count is how you read your position inside the weekly. It’s what tells you whether the weekly is running long, which way it’s translating, and whether a low is plausibly near. Put a daily mark in the wrong place and every weekly figure stays correct while your reading of them gets worse.
What it means in practice
Daily cycles can be a pain. Their signalling is frequently mixed and occasionally downright confusing, and anyone who has watched one stretch well past its window knows they’re a guide rather than a metronome. But they are a guide, and they’re an integral part of the same system — so a mark in the wrong place is a degraded read, not a cosmetic blemish.
The COIN case shows the sharp end of that. The low the indicator discarded was marginally below COIN’s confirmed weekly cycle low. Whether a margin that small means anything is a judgement call — but it’s a judgement you can only make if the chart shows you the question exists, and at the moment it doesn’t.
2. A chart that goes completely blank
This one is rarer, more alarming, and — until the fix ships — fixable by you in a second.
What you’d see
One asset, on one timeframe, draws nothing at all. No candles, no indicators, just an empty chart. The price axis down the right shows numbers that make no sense, sometimes negative. Move the crosshair around and it still reports perfectly sensible prices, which makes the whole thing look like the app has lost its mind.
The really unhelpful part: it survives restarting. Close MANTIS, reopen it, and the same asset is still blank. Every other asset is fine. It looks exactly like one asset’s data has been corrupted.
What’s actually happening
Nothing is corrupted. You’ve simply panned the chart vertically far enough that the visible price band has moved completely clear of the candles — so the candles are off-screen, and MANTIS is faithfully drawing the empty space you asked it to look at.
Because MANTIS remembers your view per asset and per timeframe, that position gets saved, which is why reopening doesn’t clear it.
The workaround — double-click the chart
Double-click anywhere on an empty part of the chart (with no drawing tool selected). That resets the vertical offset and the zoom, and your candles come straight back. The corrected view is then saved like any other, so it stays fixed.
If you’ve ever had an asset that seemed permanently broken and gave up on it, this was almost certainly why. It’s worth going back and trying it.
The fix
The daily marks now resolve to the deepest valid low in the dip, rather than to whichever one happened to catch the recovery in time. It’s already running in a sister build, where it was measured across eight assets before being accepted — one mark corrected, nothing else moved.
The blank chart is fixed at the point every path runs through: if the shifted view doesn’t overlap the candles at all, the offset is simply dropped. Panning still works right up to the edge of the data — it just can’t lose the data any more. It also repairs an already-stuck chart the moment you open it, so once that update lands you won’t need the double-click.
Both ship in the next MANTIS update. We’re not putting a date on it, because we’d rather bundle them with other work than push a release for two fixes.
If you spot either of these — or anything else that looks wrong — it’s worth telling us. The daily mark bug was found by looking at a chart and thinking “that isn’t right,” and the blank chart was found because the same asset drew perfectly in one browser and not in another. Both took a human noticing. That’s still the best bug detector we have.