Trade secrets are a unique form of intellectual property that are defined by their value and secrecy, not by any legal filing for trade secret protection.
A trade secret under Massachusetts law is defined as "specified or specifiable information" that meets two tests:
The information provides actual or potential economic advantage or value from not being generally known or readily ascertainable by others;
The information was subject to reasonable measures by the company to protect it against being acquired, disclosed, or used without consent.
Many things that would not qualify for patent protection because they are not sufficiently novel can still be protected as trade secrets, if they provide value and are carefully guarded by the company that owns them.
If you have trade secrets and somebody misappropriates them, you may bring a claim for trade secret misappropriation, in some cases even if you do not have an underlying confidentiality agreement with the person who took or used them.