Round Lot Redefinition: Stock Market's Snooze Button Moment
Published Date: 12/10/2025
Notice
Summary
NYSE Arca is updating its rules to match a new official definition of a 'round lot'—which is basically a standard group of shares for trading. This change affects traders and brokers using the exchange and takes effect right away, with no extra costs involved. It keeps things clear and consistent for everyone buying and selling stocks.
Analyzed Economic Effects
1 provisions identified: 1 benefits, 0 costs, 0 mixed.
Round Lot Sizes Aligned with Reg NMS
NYSE Arca changed its rule so the definition of a “round lot” matches Regulation NMS. Under that rule (implemented the first business day of November 2025), a round lot is: 100 shares for stocks with average closing price $250.00 or less; 40 shares for $250.01–$1,000.00; 10 shares for $1,000.01–$10,000.00; and 1 share for $10,000.01 or more. This update (filed November 25, 2025) affects traders, brokers, and investors using the exchange by changing how orders are classified as round lots, odd lots, or mixed lots.
Personalized for You
How does this regulation affect your finances?
Personalize government policy and PRIA will tell you what this federal register document means for your household, plus every other regulation we track. PRIA reads each provision against your financial profile to show you exactly what matters to your wallet.
Key Dates
Department and Agencies
Related Federal Register Documents
2026-17183, Regulation Crypto Assets
The Securities and Exchange Commission ("Commission") is proposing new rules to create a tailored offering regime for certain investment contracts involving crypto assets. The proposed offering regime is intended to facilitate capital formation and accommodate innovation within the crypto asset markets while, at the same time, ensuring that investors are adequately protected and provided with the information they need to make informed investment decisions. The proposed rules would be set forth in a new regulation titled "Regulation Crypto Assets" and would include two exemptions from the registration requirements of section 5 of the Securities Act of 1933. The first exemption would permit offerings of up to $5 million during a four-year period. The second exemption would permit offerings of up to $75 million during each 12-month period. Under both exemptions, issuers would be required to make certain principles-based narrative disclosures available to their investors. In addition, issuers under the second exemption would be required to provide financial statements and would be subject to ongoing reporting requirements. Issuers that rely on these exemptions would remain subject to the antifraud and antimanipulation provisions of the Federal securities laws. The proposed rules also would include a conditional safe harbor from the term "investment contract" in the definitions of "security" in the Securities Act of 1933 and the Securities Exchange Act of 1934. If the conditions of that proposed safe harbor are satisfied, then a crypto asset would be deemed not to be subject to an investment contract for purposes of those definitions of "security."
2026-12163, The Trade-Through Rule and Locked and Crossed Markets Provisions of Regulation NMS
The SEC wants to scrap some old rules that stop stocks from being traded at worse prices and prevent confusing market quotes. This change affects stock traders and exchanges, aiming to simplify trading and possibly speed things up. If you want to share your thoughts, you’ve got until August 17, 2026, so don’t miss out!
2026-10373, Registered Offering Reform
The SEC wants to make it easier and cheaper for more companies to sell their stocks and bonds to the public. They’re opening up special forms and benefits to more businesses, updating rules to be more modern, and cutting red tape by overriding some state rules. If you’re a company planning to raise money, these changes could speed things up and save you money, with feedback due by July 27, 2026.
2026-10222, Enhancement of Emerging Growth Company Accommodations and Simplification of Filer Status for Reporting Companies
The SEC is making it easier for companies that report their finances by simplifying their categories into just two groups: big and small filers. Smaller companies, including emerging growth ones, will get more time to file reports and enjoy simpler rules, while big companies keep stricter standards. These changes aim to save time and money, with feedback open until July 20, 2026.
2026-07651, Concept Release on Consolidated Audit Trail and Other Audit Trails and Data Sources
The SEC wants your thoughts on how it tracks stock market trades using the Consolidated Audit Trail and other data tools. They’re thinking about updating rules to keep up with new tech, privacy, and security needs, and to make sure the system is fair and cost-effective. If you’re involved in the stock market or data tracking, speak up by June 22, 2026!
2026-17058, Self-Regulatory Organizations; Nasdaq ISE, LLC; Notice of Filing and Immediate Effectiveness of Proposed Rule Change To Amend the Exchange's Connectivity Schedule and Discontinue a Previously Proposed Offering
Previous / Next Documents
Previous: 2025-22395, Self-Regulatory Organizations; NYSE Arca, Inc.; Notice of Filing and Immediate Effectiveness of Proposed Rule Change of Amendments to Rules 5.3-O and 5.4-O
NYSE Arca is updating its rules to make it easier to list options on Commodity-Based Trust Shares, joining Nasdaq ISE in this move. This change affects traders and investors by expanding the types of options available, with the new rules effective immediately. No new fees or costs are mentioned, so it’s all about more choices and smoother trading starting now!
Next: 2025-22397, Self-Regulatory Organizations; NYSE American LLC; Notice of Filing and Immediate Effectiveness of Proposed Rule Change To Amend the Rule 6800 Series
NYSE American is updating its rules to match new reporting requirements about certain stock sales called short sales. This change affects broker-dealers who must now report if a market maker claims a special exception when selling stocks short. The update takes effect immediately and helps keep trading data clear and accurate without extra costs.