Company: APM
Filing Date: 2025-12-05
Form Type: 424B5
Source: 0001213900-25-118752
Chunk: 398

Company: Aptorum Group Ltd
Filing Date: 2025-12-05
Form: 424B5
Chunk 398
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 a result
of the mark-to-market election. A U.S. Holder’s adjusted tax basis in the Class A Ordinary Shares will be increased by the amount
of any income inclusion and decreased by the amount of any deductions under the mark-to-market rules. In addition, upon the sale or other
disposition of your Class A Ordinary Shares in a year that we are PFIC, any gain will be treated as ordinary income and any loss will
be treated as ordinary loss, but only to the extent of the net amount of previously included income as a result of the mark-to-market
election.

If a U.S. Holder makes a mark-to-market
election, it will be effective for the taxable year for which the election is made and all subsequent taxable years unless the Class A
Ordinary Shares are no longer regularly traded on a qualified exchange or other market, or the IRS consents to the revocation of the election.
You are urged to consult your tax advisor about the availability of the mark-to-market election, and whether making the election would
be advisable in your particular circumstances.

The mark-to-market election
is available only for “marketable stock”, which is stock that is traded in other than de minimis quantities on at least 15
days during each calendar quarter (“regularly traded”) on a qualified exchange or other market (as defined in applicable U.S.
Treasury regulations), including NASDAQ. If the Class A Ordinary Shares are regularly traded on NASDAQ and if you are a holder of Class
A Ordinary Shares, the mark-to-market election would be available to you were we to be or become a PFIC.

If you do not make a timely
“mark-to-market” election (as described above), and if we were a PFIC at any time during the period you hold our Class A Ordinary
Shares, then such Class A Ordinary Shares will continue to be treated as stock of a PFIC with respect to you even if we cease to be a
PFIC in a future year, unless you make a “purging election” for the year we cease to be a PFIC. A “purging election”
creates a deemed sale of such Class A Ordinary Shares at their fair market value on the last day of the last year in which we are treated
as a PFIC. The gain recognized by the purging election will be subject to the special tax and interest charge rules treating the gain
as an excess distribution, as described above. As a result of the purging election, you will have