Reddit Inc. (NYSE:RDDT) stock is trading lower on Thursday, primarily due to profit-taking and a minor cooling period following a 12.5% single-day surge during the previous session. The decline follows a sharp upward move on Wednesday, which was driven by investor optimism regarding the company’s artificial intelligence data-licensing leverage. • Reddit shares are retreating from recent levels. Why is RDDT stock falling?Cooling From AI Data OptimismThursday’s downward movement represents short-term traders locking in these recent gains.Rising Short Interest DynamicsRecent market data indicate a rise in short interest for the platform. Short interest increased during the last reporting period, climbing from 13.40 million shares to 16.47 million shares. This short positioning represents 11.7% of the company’s publicly available float.Based on the recent average daily trading volume of 4.74 million shares, short sellers would require 3.47 days to close out their short positions without triggering a sharp upward movement in the stock price.Context on Recent Corporate GrowthCritical Levels To Watch for RDDT StockEven after the drop, the stock is still trading 9.8% above its 20-day SMA ($173.52) and 15.7% above its 50-day SMA ($164.62). It’s also only 3.2% above the 200-day SMA ($184.51).The moving-average structure is mixed: the 20-day SMA is above the 50-day SMA (bullish), but the stock is still living with the "Death Cross" from March (50-day SMA below the 200-day SMA), which can keep longer-term investors cautious on rallies.