The increase in short interest for Welltower suggests that investors are becoming more bearish on the stock, potentially leading to downward pressure on its price in the short term. However, being below the peer group average might mitigate some negative impact, indicating that while bearish, the sentiment is not as strong as it could be. The short-term impact is assessed as negative due to the increased bearish sentiment, but with a moderate level of confidence due to the comparative analysis with peers.