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SNAPSM Auction Requirements

What are the SNAPSM Auction requirements?

CHX will accept your order and begin a Participant-initiated SNAPSM Auction if your order meets four prerequisites – limit price, side, size, and time. If your Start SNAP Order does not meet these requirements, CHX will reject your Start SNAP Order.

Limit Price

CHX will only initiate a SNAP Auction if your order meets each of the limit price following conditions:

  • The SNAP Order’s limit price is marketable or hypermarketable at the prevailing National Best Bid and Offer (NBBO) at the time the order is received.
  • The SNAP Order’s limit price does not cross the Limit Up / Limit Down Price Band.

CHX will only initiate a SNAP Auction if your side falls in one of the following categories:

  • Buy
  • Sell Long
  • Sell Short Exempt
  • Sell Short (when regulation SHO Sell Short Restriction is not in effect)

A Start SNAP Order is of sufficient size in either of two ways:

  • A minimum of 20,000 shares
  • A minimum of 2,500 shares and an aggregate notional value of at least $250,000 (order limit price times number of shares).

If the security is subject to a special minimum Start SNAP size requirement which overrides the terms stated above, you can find the related data here, uploaded daily on our website.

CHX may adopt special size requirements for specified securities subject to SEC approval. At startup, CHX intends to set a special size requirement for Berkshire Hathaway, Inc. Class A shares of 100 shares.

Order Size Calculator

Input order limit price to calculate minimum order size.


Minimum Order Size


Input order quantity to calculate the minimum limit price required.


Minimum Limit Price


CHX will only initiate a SNAP Auction if all of the following time conditions are true:

  • The issue is open for trading in the Regular Trading Session (RTS) and not subject to a regulatory trading halt.
  • The issue has been open for trading for at least five (5) minutes since the RTS began or resumed in the RTS for at least five (5) minutes.
  • At least five (5) minutes remain before the scheduled end of RTS trading.
  • A SNAP Auction in the same security is not currently underway.
  • A SNAP Auction in the same security did not take place within sixty (60) seconds.


Get ahead with a SNAPSM Auction.