After other companies saw the profits brought by Yo-Yo, they would not let go of this opportunity to make money, and competition among Yo-Yo companies also intensified. In 1932, in order to safeguard his business interests, Duncan registered the trademark "yo-yo". Other yo-yo companies can only name their products using names such as go-go balls and swing balls. In 1946, Duncan Company was able to produce 3,600 yo-yos per hour and became the "World Yo-Yo Center". In 1960, they produced the plastic yo-yo that became commonplace. As the yo-yo craze swept the world, the federal court canceled the trademark patent rights of "yo-yo". Since then, the term "yo-yo" has spread widely and become a specialized term in the language. Unfortunately, in November 1965, Duncan Company declared bankruptcy due to poor management and was taken over by Torch Plastics Company. But the name and reputation of "Duncan" was preserved. Today, Torch Plastics still produces and sells 11 types of "Duncan Yo-Yos." Every June 6, Duncan's birthday, is designated as National Yo-Yo Day to commemorate his contribution to the yo-yo field. With the advancement of technology, the yo-yo team is also growing. In 1978, Tom Kuss created the first yo-yo with bearings that could be removed and replaced by hand. In 1980, Michelle Caffrey created the "intelligent yo-yo". Not only can it rotate freely for a long time, but its built-in centrifugal spring can make the yo-yo automatically bounce back into the hand. In the 1990s, ball bearing yo-yos also appeared, again increasing their idling time.

On April 12, 1985, the yo-yo was brought into space for the first time by NASA's "Discovery" spacecraft as part of the space toy program. Scientists have discovered that a yo-yo can move slowly and gracefully along a string in space, but it cannot stand still. Without the downward force of gravity, the yo-yo would not be able to spin and bounce back onto the string. In addition, in space, the yo-yo cannot fall freely and must be thrown. On July 31, 1992, Yo-Yo once again went into space aboard the "Atlantis" spacecraft to shoot a Yo-Yo instructional video.

Now, Yo-Yo has become popular all over the world, and many countries have established Yo-Yo associations, such as AYYA (American Yo-Yo Association), JYYA (Japanese Yo-Yo Association), HKYYFC (Hong Kong Shake Technology Association), etc.

Whether the Yo-Yo originated in China, Greece or the Philippines has been impossible to verify. It is also difficult to say exactly whether this toy has ever been spread between countries. We only know that it is unparalleled as a toy that is popular in the world and spans history. Although it sometimes disappears for a period of time, just like the characteristics of the yo-yo itself, its popularity always comes in cycles.