There are several synonyms for the phrase "most yo yo" or "very yo yo". These include unstable, inconsistent, unpredictable, erratic, fluctuating, vacillating, and wavering. These words all convey a sense of unpredictability or inconsistency, and can be used to describe situations or people who exhibit sudden changes in behavior or mood. Whether used to describe a yo-yoing stock market, an indecisive friend, or one's own emotions, these synonyms provide a range of options for expressing the idea of variability or changeability. As such, they are useful tools for effective communication in a variety of contexts.