Reverse Splits Explained: Mechanics, Fractional Shares and the 1:250 Cap

The short version

A reverse split combines several existing shares into one new share. In a 1-for-10 reverse split, every 10 old shares become 1 new share, and the share price is multiplied by roughly ten at the open on the effective date. The company's market value, your percentage ownership and the business itself are unchanged by the split alone.

Most reverse splits among small US-listed companies are about the share price, not the business. Nasdaq and NYSE American require a minimum bid price (on Nasdaq, $1.00), and a reverse split is the fastest way to lift a price back above it. Because the move is mechanical, exchanges have added rules to limit how often a company can rely on it, including Nasdaq's cumulative 250-to-1 cap over two years.

How the mechanics work

On the market effective date, the old shares stop trading and the new, consolidated shares begin trading at the open. Broker accounts are adjusted automatically. Three things change on that date:

1. The share count falls by the split ratio.
2. The price is adjusted up by the same ratio (before any trading moves it).
3. The CUSIP, the nine-character identifier for the security, usually changes, because the old security has been replaced by a new one. Nasdaq's notification form requires the company to supply the new CUSIP before the split can be processed.

The ticker symbol normally stays the same, though some data feeds temporarily append a marker to show a recent split. Options contracts on the stock are adjusted by the Options Clearing Corporation rather than cancelled.

A worked example

Hypothetical Company X has 80,000,000 shares outstanding trading at $0.40, a market value of $32,000,000. It completes a 1-for-20 reverse split.

All figures are hypothetical, before any trading on the effective date.

What happens to fractional shares

The holder in the table ends up with 502.5 shares. Most companies do not issue fractions of a share, so the split terms state how fractions are handled. The common approaches are:

• Cash in lieu. The fraction is paid out in cash, usually based on the closing price around the effective date. The holder above would keep 502 shares and receive cash for 0.5 of a share.
• Rounding up. The fraction is rounded up to a whole share. Some companies choose this to avoid cash payments, and it slightly increases the post-split share count.
• Aggregation and sale. The transfer agent pools fractions and sells them, distributing the proceeds.

The method is spelled out in the proxy statement that asked shareholders to approve the split and in the company's announcement, often an 8-K.

Why companies do it: the bid-price rule

On Nasdaq, Listing Rule 5550(a)(2) (Capital Market) and Rule 5450(a)(1) (Global Market tiers) require a minimum closing bid of $1.00. A company falls out of compliance after 30 consecutive business days below that level and receives a deficiency notice. Under Rule 5810(c)(3)(A) it then gets 180 calendar days to regain compliance, which it does by closing at or above $1.00 for at least 10 consecutive business days. A Capital Market company may be eligible for a second 180-day period.

A reverse split solves the price problem in one step, which is why it is the usual response when the price is far below $1.00. It does not change the company's cash, revenue or debts.

The 1:250 cumulative cap and other Nasdaq limits

Because a reverse split can be repeated, Nasdaq has narrowed how far it can be relied on:

• The 250-to-1 cap. Under Rule 5810(c)(3)(A)(iv), if a company fails the bid-price requirement and has effected one or more reverse splits over the prior two years with a cumulative ratio of 250 shares or more to one, it gets no compliance period. Nasdaq issues a delisting determination immediately, which the company can appeal to a Hearings Panel.
• Cumulative means multiplied. A 1-for-10 split followed by a 1-for-25 split is a cumulative 1-for-250: an original holder of 250 shares now holds one.
• The one-year rule. Since a rule change the SEC approved in January 2025, a company that fails the bid-price requirement within one year of any reverse split, of any ratio, is also ineligible for a compliance period.
• Knock-on deficiencies. If the reverse split pushes the company below another numeric listing standard (for example, the minimum number of publicly held shares), it gets no separate compliance period for that new deficiency.
• Notice requirements. Under Rule 5250(e)(7) the company must notify Nasdaq at least ten calendar days before the market effective date, and under Rule 5250(b)(4) it must publicly disclose the split by 12:00 p.m. ET at least two business days before. Nasdaq halts a stock that tries to effect a split without meeting them.

A cumulative ratio example

Hypothetical Company Y did a 1-for-8 reverse split 20 months ago and a 1-for-40 reverse split 3 months ago. Cumulative ratio: 8 × 40 = 320 to 1. If its bid price falls below $1.00 for 30 business days now, it is past the 250-to-1 cap and also within a year of its last split, so under the current rules it would receive a delisting determination rather than a compliance period.

Where reverse splits show up in filings

• Proxy statement (DEF 14A or PRE 14A). Shareholders are usually asked to approve a range of ratios (for example, 1-for-5 to 1-for-50), leaving the board to pick the final one.
• 8-K, often Item 5.03 (amendments to articles of incorporation) and Item 3.03 (material modification to rights of security holders), announcing the ratio and effective date.
• Exchange notices. Nasdaq lists upcoming splits on its Daily List for the two business days before the effective date.
• The next 10-Q or 10-K, where share counts and per-share figures are restated.

How to check a company on Signal8

• The delisting screener groups companies with listing compliance issues, the context in which most reverse splits are proposed.
• The live SEC filings feed shows proxy statements and 8-Ks as they are filed.
• A company's filings tab lists its historical filings, where earlier split ratios can be found.

For what a reverse split does and does not do to existing dilution, see What Is Dilution?.

FAQ

Does a reverse split change the value of my shares?

On its own, no. A reverse split divides the share count and multiplies the price by the same ratio, so the market value of a holding and the percentage ownership are unchanged at the moment it takes effect. The price after that depends on trading, and any fractional share is usually paid out in cash or rounded according to the split terms.

What happens to fractional shares in a reverse split?

The split terms decide. The most common treatment is cash in lieu, where the fraction is paid out in cash based on a market price around the effective date. Some companies round fractions up to the next whole share, and some have the transfer agent aggregate and sell the fractions. The method is stated in the proxy statement and the company's announcement.

What is Nasdaq's 250-to-1 reverse split rule?

Under Nasdaq Listing Rule 5810(c)(3)(A)(iv), a company that falls below the $1.00 bid price after effecting reverse splits with a cumulative ratio of 250 to 1 or more over the prior two years is not given a compliance period. Nasdaq issues a delisting determination immediately, which the company may appeal. The ratios of separate splits are multiplied together to get the cumulative figure.

Why does the CUSIP change after a reverse split?

The CUSIP identifies a specific security. A reverse split replaces the old shares with a new, consolidated security, so it normally receives a new CUSIP even though the ticker usually stays the same. Nasdaq requires the company to provide the new CUSIP, already made eligible at DTC, before it will process the split.