A 1-for-20 turns 20 shares into 1.
Charter limit. Usually unchanged by the split.
Post-split price  
Post-split shares  
Market cap Unchanged by the split
Your position Enter your share count
Newly issuable shares Authorised minus outstanding, after split
Issuable value At the post-split price

The number people miss

Look at newly issuable shares. A reverse split shrinks shares outstanding but almost never shrinks the authorised count — so the gap between them explodes. A company at 180 million of 500 million authorised has 320 million shares of headroom. After a 1-for-20 it has 9 million outstanding against the same 500 million authorised: 491 million shares of headroom, at twenty times the price. That is the point of the exercise far more often than “attracting institutional investors” is.

What a reverse split actually does

Nothing, economically. Twenty shares at $0.18 become one share at $3.60. You own the same fraction of the same business. Market cap is unchanged, and so is every ratio derived from it.

What changes is eligibility:

ThresholdWhat it unlocks
$1.00 minimum bidContinued listing on Nasdaq or NYSE. Below it for 30 consecutive business days triggers a deficiency notice and a compliance clock.
$5.00Margin eligibility at many brokers, and some institutional mandates that prohibit holding stocks below it.
$75M public floatNot unlocked by a split. The baby shelf rule keys off the value of public float, and a split multiplies the price and divides the share count by the same factor — so float value is identical afterwards. Only a genuine rise in the stock clears this one.
Authorised headroomRoom to issue — see above. The real motivation more often than not.

The pattern to expect

  1. Bid price falls below $1.00

    A deficiency notice arrives and is disclosed in an 8-K under Item 3.01. The compliance period is typically 180 days, sometimes with a second 180 available.

  2. A proxy proposes a reverse split

    Often with a range of ratios at the board's discretion, and sometimes alongside a proposal to increase authorised shares. The vote result appears in an 8-K under Item 5.07.

  3. The split executes and compliance is regained

    Typically requires closing at or above $1.00 for around ten consecutive business days.

  4. A financing follows

    Frequently within weeks. The listing is compliant, the price supports a raise, and the authorised headroom is now enormous. Watch for an S-3, a 424B5, or an ATM sales agreement.

Two things to watch for

Screeners will show a brand-new “low float” stock. A 1-for-20 turns a 120-million-share float into 6 million. Nothing has become scarce. Anyone screening for thin floats without checking the filing history will find these and mistake them for setups.

Serial reverse splits are the real signal. One may be a genuine one-off. Two or more in a few years describes a company that has repeatedly diluted to the point of non-compliance and reset the counter each time.

Read next

For where these show up in the filings, see how to read an SEC filing. For why the post-split float reading misleads screeners, see float and short interest explained. To model the raise that usually follows, use the dilution calculator.

Disclaimer

A general educational tool performing arithmetic on figures you supply. Not investment advice and not a prediction about any company's intentions. Listing standards and thresholds are summarised and change over time; consult the exchange's own rules. See our full disclosures.