IPO Day Explained

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IPO Process Library · 07 Allocation & IPO Day

Last Updated | November 11, 2026

What Happens on IPO Day?

IPO day begins long before the first trade. Pricing is set the night before, and the stock opens after an exchange-run auction. Shares are priced after the market closes the day before, trading starts after an opening auction, and the price can differ sharply from the offer price.

Key Takeaways

• Pricing occurs before the first trade.
• The exchange sets the opening price through an auction.
• The offer price and opening price are different things.
• Stabilization can support weak trading.

Before the OpenThe OpeningThrough the CloseIPO Day SequenceFAQRelated

01

Before the Open

After the final order book, the company and lead banks agree on the price, sign the underwriting agreement, and the final prospectus is filed. Banks confirm allocations and notify investors.

02

The Opening

Exchanges run an opening process that matches buy and sell interest to set the first trade price. This can take hours for high-demand deals, and the opening price can sit well above or below the offer price.

03

Through the Close

Stabilization by the lead bank may support the price if it falls toward the offer. Closing price, volume, and performance versus the offer price are reported that evening. Settlement of IPO shares typically follows shortly after.

04

IPO Day Sequence

When	What happens
Prior evening	Final pricing and agreement signed
Morning	Exchange opening process
Trading hours	First trade and price discovery
Close	Closing price and any stabilization

05

Common Questions

When can I buy shares?

Once trading opens, through a brokerage account.

Why does the open differ from the offer price?

The offer price is set by banks; the opening price reflects supply and demand.

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Keep Reading

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Methodology & Sources
Synthesizes SEC rules and guidance (Securities Act of 1933, Exchange Act of 1934, Regulation S-K), NYSE/Nasdaq listing standards, FINRA rules, and public S-1 filings. Cross-checked against primary documents. Rules, thresholds, and timelines change; confirm current requirements with counsel before acting. General education, not legal or investment advice.

Author: Erwin Castro