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Quantum-Si (QSI) After-Hours

DateAfter-hours PriceAfter-hours HighAfter-hours Low
Sep 9, 2025$1.12$1.16$1.12

Data last updated Sep 9, 2025 6:30 PM EST.

Quantum-Si (QSI) After-Hours Trading Summary

As of 6:30:00 PM EST on September 9, Quantum-Si (QSI) is trading at $1.12 in the after-hours session, down -$0.03 (-2.45%) from the regular market close of $1.15.

During after-hours trading, Quantum-Si (QSI) stock has ranged between $1.16 and $1.12, with the most recent trade recorded at $1.12.

After-hours trading

How to Buy or Trade Quantum-Si (QSI) After Market Close

Looking to trade Quantum-Si stock (QSI) after the market closes? Public offers access to after-hours trading from 4:00 PM to 8:00 PM ET, giving investors the flexibility to place trades outside of regular market hours. Keep in mind that extended-hours trading may involve lower liquidity and wider bid-ask spreads than normal sessions. Follow the steps below to get started.

  1. 1

    Create a Public brokerage account

    Sign up for a free brokerage account with Public. You can open an account directly on the website or by downloading the Public app for iOS or Android.

  2. 2

    Deposit funds into your account

    Add funds to your Public account by linking a bank account, using a debit card, or initiating a wire transfer, so you’re ready to invest during extended hours.

  3. 3

    Find Quantum-Si (QSI) stock and place your after-hours order

    Go to the Explore tab and type “Quantum-Si” or “QSI” into the search bar. Select the stock from the results to view its quote page. From there, you can enter the amount you’d like to invest and place an after-hours order directly.

  4. 4

    Track your Quantum-Si (QSI) shares in your portfolio

    Once your order is executed, Quantum-Si (QSI) will appear in your portfolio. You can track your QSI shares alongside other assets—including stocks, ETFs, crypto, bonds, options, and your high-yield cash account—all in one place on Public.

Quantum-Si (QSI) After-Hours Price History

DateMarket close priceAfter-hours priceChange
Sep 9, 2025$1.15$1.12-2.45%
Sep 8, 2025$1.06$1.07+0.94%
Sep 5, 2025$1.08$1.07-0.92%
Sep 4, 2025$1.07$1.070.00%
Sep 3, 2025$1.07$1.06-0.93%
Sep 2, 2025$1.08$1.080.00%
View all

FAQs About Quantum-Si (QSI) After hours

As of 6:30 PM ET Sep 9, 2025, Quantum-Si (QSI) is trading at $1.12 in the after-hours session, down -$0.03 (-2.45%) from the regular market close of $1.15. After-hours prices reflect trading activity that occurs after the market closes at 4:00 PM ET.

Quantum-Si (QSI) is currently trading down in the after-hours session, with a price of $1.12, which is -$0.03 (-2.45%) lower than the regular close of $1.15. After-hours movement shows how the stock is performing outside of normal trading hours.

In the latest after-hours session, Quantum-Si (QSI) has traded between a low of $1.12 and a high of $1.16. These prices reflect extended-hours activity after the regular session ends.

After-hours trading for Quantum-Si (QSI) on Public begins at 4:00 PM ET and runs until 8:00 PM ET. These extended trading hours allow you to place orders beyond the regular market close, though price volatility and liquidity may vary.

You can trade Quantum-Si (QSI) after hours through brokerages that offer extended-hours trading, including Public. After-hours access on Public is available from 4:00 PM to 8:00 PM ET. Get started with a Public brokerage account to trade QSI after the market closes

Quantum-Si (QSI)

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