The downgrade from Overweight to Neutral by a major analyst like JP Morgan suggests a more cautious view on Garmin's stock, potentially leading to a less bullish sentiment among investors in the short term. However, the price target of $135 still implies some upside from current levels, indicating that the downgrade is not necessarily a bearish signal but rather a moderation of expectations. The impact on the stock price may be mixed, as the market digests both the downgrade and the price target.