ATM Offering — At-the-Market
An at-the-market (ATM) offering is a continuous equity issuance program that allows a public company to sell newly registered shares directly into the open market at prevailing prices, through a broker-dealer acting as agent. ATM programs give micro-cap companies a flexible capital tool — without the upfront discount, lockup period, or dilution overhang associated with traditional secondary offerings.
How an ATM Program Works
The company first files an effective Form S-3 shelf registration with the SEC, registering a specified number (or dollar value) of shares for future issuance. It then enters into an equity distribution agreement with one or more broker-dealers (the "agents"), who are authorized to sell shares on the company's behalf at market prices during regular trading hours.
The company controls when and how much stock is sold — it can instruct the agent to sell on specific days, at minimum price thresholds, or within defined volume limits. Quarterly, the company files a prospectus supplement disclosing the amounts sold and proceeds received. ATM activity is also tracked in the 10-Q and 10-K.
ATM vs. Traditional Secondary Offering
ATM Advantages
- No underwriting discount (typically 2–3% agent commission vs. 5–7% deal discount)
- No deal lockup on existing holders
- Flexible timing — sell when the stock is performing well
- No roadshow or wall-cross process required
- Minimal dilution overhang — no announced "deal size"
ATM Limitations
- Requires effective S-3 shelf registration (not available to all micro-caps)
- Raises less capital per period than a traditional deal
- Ongoing selling pressure if not managed carefully
- Disclosure requirements in every periodic filing
- Market surveillance systems track ATM volume patterns
S-3 Eligibility for Micro-Caps
To access an ATM program, a company must first qualify for and file an effective Form S-3 registration statement. S-3 eligibility requires:
- At least 12 months of continuous SEC reporting as a public company
- Timely filing of all required SEC reports for the prior 12 months
- For the primary offering of securities for cash: a public float of at least $75 million (the "baby shelf" rule under Rule 415); companies below this threshold are subject to the 1/3 rule limiting their annual primary offering to one-third of their public float
Many newly public de-SPAC companies and micro-caps below $75M in public float can still access limited ATM programs under the 1/3 rule — but must manage their aggregate issuance carefully to avoid violating the limitation.
IR Considerations When Running an ATM
Investors and algorithms track ATM utilization patterns closely. Best practices for micro-cap IR teams running ATM programs include:
- Disclose the program size and purpose upfront in an 8-K when you establish the agreement
- Limit daily selling volume to minimize market impact (typically well under 10% of average daily volume)
- Avoid selling on the day of or immediately after a major positive announcement — this can be perceived as management monetizing positive news at investors' expense
- Communicate use of proceeds clearly so investors understand the capital is going toward value creation, not covering operating losses with no recovery path
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Run Free Score →Informational only — not legal or investment advice. ATM program eligibility and structure involve complex securities law considerations; consult qualified securities counsel. See our Disclaimer.