Why National Instruments Stock Popped 10% Today

Shares of scientific software maker National Instruments (NASDAQ: NATI) soared 9.7% through 1 p.m. ET on Wednesday -- but if you want to buy into this rally, you had better act quickly. This morning, National Instruments rival Emerson Electric (NYSE: EMR) announced it has signed a "definitive agreement" to acquire National Instruments for $60 per share in cash -- or $8.2 billion in total. Emerson noted that National Instruments did $1.66 billion in business last year, which results in a price-to-sales (P/S) ratio of 4.9 on the acquisition -- or roughly twice the valuation of Emerson's own shares (which sell for a P/S ratio of 2.5).