Taiwan Semiconductor ( [TSM](//research.investors.com/quote.aspx?symbol=TSM) ) stock had its [Relative Strength (RS) Rating](//www.investors.com/ibd-university/find-evaluate-stocks/exclusive-ratings/) upgraded from 70 to 76 Wednesday — a welcome improvement, but still below the 80 or higher score you look for. When looking for the [best stocks to buy and watch](//www.investors.com/how-to-invest/investors-corner/looking-for-the-best-stocks-to-buy-and-watch-start-here/) , one factor to watch closely is relative price strength. IBD’s unique rating measures price movement with a 1 (worst) to 99 (best) score. The score shows how a stock’s price behavior over the trailing 52 weeks compares to all the other stocks in our database. Over 100 years of market history reveals that the stocks that...