An IPO lockup expiration is the date when insiders and pre-IPO holders are finally allowed to sell shares they agreed not to sell after the offering; it is usually about 180 days after the prospectus date, but the real date is whatever the 424B4 prospectus says. That last clause is the whole game. In 2026 alone, BitGo's earnings clause, applied to its May earnings date, pulled its insider lock-up end into May instead of July, Cerebras's schedule runs to 11 release dates, and Janus Living's main holders signed up for 365 days. Read the filing, not the folklore.

What a lockup actually is (and is not)

Investor.gov defines lockup agreements as restrictions that "prohibit company insiders—including employees, their friends and family, and large shareholders—from selling their shares for a set period of time after an IPO." The insiders and the underwriter "typically enter into" the agreement before the company lists. In other words, it is a contract with the banks, not an SEC rule. That is why the lead underwriter can waive it, and why the terms differ deal to deal.

What the law does require is disclosure. Per Investor.gov, "most prevent insiders from selling their shares for 180 days," lockups may also cap how many shares can be sold over time, and U.S. securities law requires the company to disclose the terms in its registration documents, including the prospectus.

Where to look in the final prospectus (the 424B4 on EDGAR):

• "Shares Eligible for Future Sale": how many shares unlock, and when.
• "Underwriting": the legal wording, who signed, who can waive, and any early-release triggers.
• The cover and the last page: the prospectus date. Every "180 days after the date of this prospectus" clause counts from that date, not from the first trade.

Early releases: the clauses that move the date

The plain 180-day lockup is no longer the only template. Three variants showed up in 2026 prospectuses:

• Earnings-based termination. The BitGo ($BTGO) 424B4, dated January 21, 2026, says the lock-up for directors, officers, selling stockholders and other holders ends "on the open of trading on the second trading day" after the company reports earnings for the second quarter following the latest period in the prospectus. That period was the nine months ended September 30, 2025, so the trigger was Q1 2026 results. BitGo reported those on May 13, 2026 (8-K), which puts the release at the open on May 15, 2026, about two months before day 180.
• Price-based partial releases. The same BitGo filing would have released 5–10% of some holders' shares early if the stock closed at least 30% above the $18.00 IPO price. Arithmetic: $18.00 × 1.30 = $23.40. BitGo's highest FMP close after listing was $18.49 on January 22, 2026, so that trigger could not have fired.
• Blackout-driven pull-forwards. Forgent Power Solutions ($FPS) ends its 180-day period early, ten trading days before an insider-trading blackout, if day 180 would otherwise land inside or just before one. Janus Living ($JAN) goes the other way. Healthpeak, the manager, officers, directors and substantially all other holders agreed to 365 days, not 180.

Four 2026 IPOs whose lockups have passed

We pulled each 424B4, read the actual term, and dated the first session in which locked shares could be sold. EquipmentShare ($EQPT), Bob's Discount Furniture ($BOBS) and York Space Systems ($YSS) are straight 180-day lockups from prospectus dates of January 22, February 4 and January 28, 2026. York's filing says shares are eligible "beginning 181 days after the date of this prospectus." BitGo uses its earnings-based date. Prices are FMP daily closes in US$.

The percentage math, run-up first, then follow-through:

• $EQPT: 17.34 ÷ 17.64 − 1 = −1.7% into the unlock, then 17.96 ÷ 17.34 − 1 = +3.6% after. The stock actually rallied to $19.40 the day after the unlock. Versus the IPO price at the October 19, 2026 close: −43.1%.
• $YSS: −0.9% into the unlock, then 15.31 ÷ 17.81 − 1 = −14.0% after. The next session closed at $15.02, down 15.7%. Versus IPO: −83.3%.
• $BOBS: 18.52 ÷ 17.00 − 1 = +8.9% into the unlock, then −0.9% after. Versus IPO: −10.8%.
• $BTGO: 8.89 ÷ 12.57 − 1 = −29.3% into the unlock, then 6.93 ÷ 8.89 − 1 = −22.0% after. Versus IPO: −68.8%.

Volume is the one consistent signal. Unlock-session volume against the prior 20-session average (arithmetic from FMP volume):

• $EQPT: 6,855,600 vs 3,367,795, or 2.0x.
• $YSS: 2,067,565 vs 1,027,264, or 2.0x, and 4,325,886 the next day.
• $BOBS: 1,453,244 vs 939,633, or 1.6x.
• $BTGO: 3,201,700 vs 575,470, or 5.6x.

Now the honest part. Two of the four were higher five sessions after the unlock than five sessions before ($EQPT, $BOBS), and two were sharply lower. The two biggest moves are also contaminated by earnings. BitGo's unlock was defined by its May 13 report, and the −29.3% run-in includes the May 14 gap from $11.91 to a $10.70 open. Bob's reported quarterly results on August 6, inside its post-unlock window. All four sit below their IPO price, but that is a statement about the 2026 IPO class as much as about lockups: $FPS closed at $31.52 on October 19, 2026, 16.7% above its $27.00 IPO price, and $JAN at $28.64 against $20.00. A lockup date is a supply event, not a verdict.

Upcoming unlocks, straight from the prospectuses

These are filing dates and share counts only, as of October 20, 2026. They are not forecasts.

• Cerebras ($CBRS), prospectus dated May 13, 2026, uses a staggered schedule. Up to approximately 19.4 million shares become eligible at 6:00 a.m. ET on October 28, 2026. All remaining locked shares follow on the earlier of the second trading day after Q3 2026 earnings or 180 days after the prospectus date. Arithmetic: May 13 + 180 days = November 9, 2026.
• SpaceX ($SPCX), prospectus dated June 11, 2026, lists these tranches:
  • Up to 328.4 million shares on October 24, 2026 (the 135th day).
  • Up to 1.3 billion shares (28% of the 180-day pool) on the second full trading day after Q3 2026 results.
  • On December 8, 2026 (day 180), either 328.4 million or 797.6 million shares, depending on whether a price-triggered early release fired in August. That release required closes at least 30% above the $135.00 offer price ($175.50, arithmetic) on five of the ten sessions ending on the first earnings date. SpaceX's Q2 earnings release was dated August 4, 2026, and FMP closes in that window topped out at $125.33.
  • Elon Musk's shares, up to 6.4 billion, are locked for 366 days, to June 12, 2027, with no early-release provisions.
• Bob's ($BOBS) also has a second layer. A stockholders agreement restricts certain holders for 270 days from February 4, 2026. Arithmetic: November 1, 2026.

For more on how the stock has traded since listing, see our earlier piece on SpaceX slipping below its IPO price.

How traders track a lockup

1. Pull the 424B4. Note the prospectus date, the exact wording ("180 days after" vs "beginning 181 days after"), every early-release trigger, and who can waive.
2. Size the supply. Bob's 424B4 shows 108,988,185 locked shares against 19,450,000 sold in the IPO, about 5.6 times the IPO float (arithmetic). See float vs. outstanding shares for why that ratio matters.
3. Watch Form 144. Per the SEC's Rule 144 guide, an affiliate must file Form 144 when a sale exceeds 5,000 shares or $50,000 in any three-month period. EquipmentShare's first post-IPO Form 144s hit EDGAR on August 14 and 18, 2026, about three weeks after its unlock. Cerebras's started on August 14, 2026, two trading days after its August 12 earnings release, which matches its schedule.
4. Check S-8 and resale registrations. S-8s register employee-plan shares. S-3 or resale S-8 filings can make holder shares freely tradable. EquipmentShare filed its S-8 on January 26, 2026, the day its 424B4 was filed.
5. Mark the calendar against earnings. When an unlock sits next to a report, as BitGo's and Bob's did, the price move cannot be pinned on the lockup alone.

Reverse mergers have lock-ups too

De-SPACs and reverse mergers often use tiered releases instead of one cliff. Powerus ($PUSA) is a live example. Its 424B3 says lock-up shares release in thirds: at closing, at 90 days and at 180 days. The merger closed on October 1, 2026, and an S-3 filed October 19 registers a 7,409,209-share resale. The full share-count walk-through is in Powerus PUSA stock after the merger. More deal coverage lives in our IPO section and on the I'M A STOCK TRADER homepage.

FAQ

How long is a typical IPO lockup?

Investor.gov says most lockups prevent insider sales for 180 days, but terms vary. In 2026 filings we found earnings-based early endings (BitGo), staggered schedules (Cerebras, SpaceX) and 365-day terms (Janus Living, SpaceX's Elon Musk).

Where do I find the lockup expiration date?

Open the company's 424B4 on SEC EDGAR, find the prospectus date, then read the "Shares Eligible for Future Sale" and "Underwriting" sections for the exact term and any early-release triggers. Count from the prospectus date.

Does the stock always drop when the lockup expires?

No. Of four 2026 IPOs reviewed here, $EQPT and $BOBS were higher five sessions after the unlock than five sessions before, while $YSS and $BTGO were lower. Volume rose on the unlock session in all four.

Can a lockup end early?

Yes. The underwriters can waive it, and many prospectuses build in early releases tied to earnings dates or the share price. BitGo's insider lock-up, for example, ended at the open on May 15, 2026, applying its earnings clause to the May 13 results date.