SWR: verb for what a policy aims to do

To say that the policy "deters" insider trading might have the more formal tone you are looking for. "Indemnifies [the company]" has a loftier sound but a specific legal denotation which might not be exactly what you intend.

"Safeguards [against]," "insures [against]," "inhibits," "prevents," "impedes," or "thwarts" are some other possibilities.

This policy militates against insider trading and market manipulation.

militate against [formal]: to make (something) unlikely to happen : to prevent (something) from happening

• His inexperience militates against his getting an early promotion.
• factors militating against success

[Merriam-Webster]

Policies penalize non-compliance.

Policies are set with the hope of preventing or discouraging certain actions through the expectations that participants wish to avoid the consequences of being caught in violation.

This policy penalizes insider trading and market manipulation.

The policy may (or may not) prove to be an effective deterrent.

From MW: penalize

to punish someone for breaking a rule:
He was penalized early in the game for uunsportsmanlike conduct.