Tactile Systems Technology (NASDAQ:TCMD) is down 9.8% over the past month. However, stock prices are usually driven by a company’s financials over the long term, which in this case look pretty respectable. The formula for return on equity is: Return on Equity = Net Profit (from continuing operations) For every $1 worth of equity, the company was able to earn $0.15 in profit. This is based on how much of its profits the company chooses to reinvest.