Normally, it would have a negative connotation. If you say someone is "opportunistic," it usually something like "sneaky" and "self-serving," like the person is looking for ways to build themselves up in the company, usually at the expense of others. Example: Frank is really opportunistic. He is always looking for ways to kiss up to the boss.

It can mean both, but usually it is used in a very condescending way. As a person who takes full advantage of a situation for their own personal benefit.

It simply means someone who takes advantage of opportunities. The context will decide whether it is positive or negative. Example: John was opportunistic enough to find a new job within 24 hours of being fired. (positive use) Example: The paedophile was being opportunistic when he kidnapped the children from the park. (negative use)

opportunistic is an adjective that derives from the noun "opportunity. this is when you take the opportunity to do something. one who be considered an opportunistic person can be someone smart, intelligent and good for business. to the other hand, I think this adjective can have bad connotations when people do not have limit or principles, betraying other people or passing the leg on someone