Bittrex:

Due to the large number of leaked username and password databases, we are making changes to withdrawals to limit the damage of unauthorized access to your account. This is not a substitute to having strong and unique passwords, protecting your email account, and having 2 factor authentication on your Bittrex account. Bittrex strongly encourages you to have 2 factor authentication.

Withdraw Limits

  • If your password has been changed, you cannot make a withdrawal for 24 hours

  • If your account does not have 2FA, you are limited to withdrawing up to 1 BTC (or equivalent) per day

  • If you have an account created after October 30th, 2016, your withdrawal limits are:

    • Unverified Accounts created before 08/01/17: 0.025 BTC (or equivalent) per day
    • Unverified Accounts created on or after 08/01/17: 0 BTC (or equivalent) per day
    • Basic Accounts: 3 BTC (or equivalent) per day with two-factor enabled.
    • Enhanced Accounts: 100 (or equivalent) BTC per day with two-factor enabled

Source: https://support.bittrex.com/hc/en-us/articles/231701788