Dilutive securities are any financial instrument that can increase the
number of shares a company has outstanding. There are many
examples of such as preferred stocks, convertible bonds and warrant
stocks. The outcome that you get from dilutive securities is to
reduce cost of shares and earnings.
Antidilutive is a term that explains actions, such as certain retirement
securities, conversion securities, or other actions that are made on
the corporate level that pertain to EPS. "Antidilutive activities
maintain or increase the voting power or EPS for existing
shareholders by lowering the company's outstanding share count or
increasing the company's earnings"(investopedia).
From a shareholder point of view it would be of more value to have a
antidilutive securities instead of dilutive securities in a company.
https://smartasset.com/investing/dilutive-securities
https://www.investopedia.com/terms/a/
antidilutive.asp#:~:text=Dilutive%20vs.,or%20activities%20that
%20reduce%20EPS.