Intuitive Surgical‘s ISRG six-month share-price performance reflects a tug-of-war between sustained demand for robotic-assisted surgery and investor concerns about valuation, competitive threats and the company’s profitability. The latest operating results reinforce the strength of its underlying business, but a substantial litigation settlement has complicated the earnings picture.

The stock has risen 7.8% over the past six months, underperforming the Zacks Medical – Instruments industry’s 28.7% gain. The stock has fared better than the S&P 500 Index’s 2% decline. Over the past six months, ISRG has lagged its industry peers, Medtronic MDT and Johnson & Johnson JNJ, which have recorded share price gains of 36.5%…