Charles River's stock movement is possibly a direct reaction to Danaher's financial performance, as strong results from companies within the same or related sectors can often lead to sympathetic movements in the market. Given that Danaher reported better-than-expected results, investors might be optimistic about Charles River's prospects, leading to a short-term positive impact on CRL's stock price.

Danaher's positive earnings report for Q1 could have a broader impact on the market, especially on stocks within the same sector or those that are closely related. The better-than-expected financial results may lead to increased investor confidence not only in Danaher but also in companies like Charles River, which could see a sympathetic rise in their stock prices as a result.