There are several synonyms for the phrase "most speculating" including "highly conjectural", "theorized", "hypothetical", and "presumed". Each of these terms suggests a level of uncertainty or likelihood that something is true. "Highly conjectural" indicates that something is based on guesswork or incomplete information, while "theorized" suggests that a theory has been proposed but has not been proven. "Hypothetical" implies a situation or scenario that is imagined but not necessarily true, while "presumed" suggests that something is believed to be true without sufficient evidence to confirm it. All of these synonyms convey a level of uncertainty or ambiguity, making them useful in discussing hypothetical scenarios, potential outcomes, or unproven claims.