FINRA's guidance on this point is clear. As you may know, Form U4 asks if the applicant has ever been charged with any felony, and whether convicted of any felony. Some exam candidates confuse the “ever” with a 10-year period looking back from the date of application. They mistakenly think if a felony conviction occurred 12 years ago, the applicant can answer “No” to these questions/items. Turns out, any felony charge and any felony conviction must be disclosed, no matter how long ago it took place. Failing to disclose the information is a game-over for any state regulator, the SEC, or FINRA, too.
What about a pardon? An individual pardoned was, first, convicted of the crime. And, he/she was, also, formally charged with the crime. So, as nice as it must be to get out of prison sooner than expected, the pardon does not change either answer on Form U4. Yes, the pardoned individual was both charged and convicted of a felony offense.