While the increase in short interest for DexCom indicates that more traders are betting against the stock, it is not a certain indicator of future price movement. The market may interpret this as a sign of potential weakness, but it could also lead to a short squeeze if the stock moves contrary to the short sellers' expectations. The relevance is high as the article is directly about DexCom's short interest, and the importance is significant due to the potential impact on stock volatility. The confidence level is moderate because market sentiment can be unpredictable and does not always correlate with immediate price changes.