Meme coins POPCAT and MOG surged over the weekend, driven by cat-themed narratives and traders’ testing bets, CoinDesk reported. POPCAT’s market value briefly topped $1 billion, making it the winner of Polymarket’s popular bets.

The two coins have risen along with dog-themed tokens BONK and DOGE since earlier this year as leveraged bets on the growth of their underlying blockchains. POPCAT, which is based on Solana, surpassed $1 billion in market cap following a $630,000 purchase late Sunday.

Meanwhile, Ethereum-based MOG rose 8% to a new high of $960 million in market value. Polymarket’s bets on the market value of cat-themed tokens have seen $4.6 million in trading volume since its launch in March.

However, some Polymarket users believe that market manipulation may have affected the outcome of POPCAT bets. Nonetheless, Polymarket’s resolution remains in place and has not been challenged as of Monday morning European time.