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Lesson 6 of 7
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Lesson 6 · 9 min · BriMindInvest Research Team

Lock-Up Expiry: Reading the Clause and Doing the Flow Math

Cliff, staged and earnings-linked lock-ups, where the share count comes from, and the one calculation that tells you whether an unlock is absorbable — shares released divided by average daily volume.

In this lesson you'll learn
Where the lock-up clause sits in a prospectus and how to read it
The four structures, and which two break a calendar assumption
Shares unlocking ÷ average daily volume, and what that ratio does and does not say
Why a call needs a fixed horizon and a baseline to mean anything

The one date in a new listing you can know in advance

Almost nothing about a newly public company is predictable. The lock-up expiry is the exception: it is written into a public document on pricing night, months before it happens, and it marks the day a large block of shares becomes legally sellable.

The current radar reads that clause out of the prospectus rather than assuming a date — 107 prospectuses so far, producing 81 covered listings, of which 47 have terms clean enough to publish and 183 are withheld.

Note the ratio of withheld to publishable. Roughly a third of prospectuses state the terms in a way we will not reduce to a date and a share count without guessing, so those are held back with the reason. The alternative — publishing the guess — is what makes most lock-up calendars unreliable.

Four structures, two of which break a calendar

StructureCountWhat it means for the date
cliff72Cliff — one date, everything at once
unknown5Stated but not machine-readable — withheld rather than guessed
earlier-of3Earlier-of — a date, or an earnings release, whichever comes first
staged1Staged — releases in tranches on separate dates

The cliff majority is why "180 days" usually works. The minority is why it is not good enough: an earlier-of clause can release shares months ahead of the assumed date when an earnings release triggers it, and a staged release spreads supply across several dates that a single-date calendar never shows.

A staged release, read out of the document

Cerebras Systems Inc. (CBRS) releases in tranches. The radar reports 400,220,690 shares unlocking at the first date — derived from the filing's share counts — leaving a residual 53.2% still restricted afterwards. A calendar that printed one date and one total for this listing would be wrong twice.

Underwriters can also release a lock-up early at their discretion, and sometimes do. No reading of the clause protects you from that. What the clause gives you is the latest plausible date and the size of the block — which is far more than a guess.

The flow math

The supply question has a one-line answer. Take the shares becoming sellable and divide by how many shares trade on an average day:

shares unlocking ÷ average daily volume = absorb days

That number is how many full sessions of the stock's entire normal volume it would take to absorb the block, if all of it came to market. It will not. But the ratio separates listings where the unlock is a rounding error from ones where it dwarfs the float.

ListingExpiryShares unlockingAvg daily volAbsorb daysResidual locked
SPTX
Seaport Therapeutics, Inc.
2026-10-2838,867,817264,070147.2100.0%
ALMR
Alamar Biosciences, Inc.
2026-10-1455,271,425429,930128.6100.0%
AVLN
Avalyn Pharma Inc.
2026-10-2725,145,380254,16098.9100.0%
XE
X-Energy, Inc.
2026-10-24348,095,2097,430,94046.8100.0%
CBRS
Cerebras Systems Inc.
2026-11-10400,220,6905,839,44036.553.2%
ARXS
Arxis, Inc.
2026-10-1323,153,980864,24026.8100.0%
FRVO
Fervo Energy Co
2026-11-10205,005,1858,171,95525.1100.0%
GMRS
GMR Solutions Inc.
2026-11-1022,106,8351,059,21020.9100.0%
ELMT
Elmet Group Co.
2026-10-2020,276,2211,271,01016100.0%

Read the last column alongside the absorb days. A big block with a big residual means more is still coming; a big block with a small residual means this is the whole event.

What makes a call testable

It is easy to say "watch out for the lock-up" and impossible to be wrong about it. A claim only means something if it commits in advance. The radar's rules, stated before any date arrives:

  • Issued in a fixed window. 15–45 days before expiry — early enough to be a forecast, late enough for volume to be meaningful.
  • Never backfilled. A call cannot be created for a date that has already passed. 9 calls are currently open and awaiting their dates.
  • Graded at fixed horizons. +5 and +21 sessions after expiry, decided by the rule rather than by inspection.
  • Scored against a naive baseline. The comparison is "180-day cliff, absorb-days threshold". If the simple rule does as well, the elaborate one earned nothing — and the scoreboard says so.

A large unlock is not a short thesis. Insiders frequently sell nothing, the event is widely known, and prices often move ahead of the date rather than on it. The honest use of this data is as a reason to wait before buying a recent listing, not as a trade.

Open calls, the quoted clause behind each one, and the graded results as dates pass: /lockup-radar.

Quick Knowledge Check
3 questions · test what you've just learned
1

A stock trades 2,000,000 shares a day. At lock-up expiry, 60,000,000 shares become sellable. What is the absorb-days figure, and what does it mean?

2

Why does reading the actual prospectus clause beat assuming '180 days from the IPO'?

3

A call issued 30 days before expiry says 'absorbed'. Two months later the stock is down 20%. Was the call wrong?

✓ Key takeaways from Lesson 6
The lock-up terms are in the underwriting section of the final prospectus. Read them; do not assume 180 days.
Absorb days = shares unlocking ÷ average daily volume. It measures potential supply against normal liquidity, not direction.
The residual percentage matters as much as the raw share count: an unlock that frees most of the company is a different event from one that frees a sliver.
Any claim about an unlock must state its horizon before the date and be graded against a naive baseline afterwards — otherwise it is unfalsifiable.
The live radar

Open calls with the prospectus clause quoted, the expiry date, shares unlocking, absorb days, and the graded scoreboard for calls that have already expired.

Open the lock-up radar →
← Lesson 5: How an IPO Actually Works, From S-1 to First TradeNext: Lesson 7 — Writing Your Own Pre-IPO & IPO Policy →