The Los Angeles Business Journal’s index of largest local public companies fell for the week as investors reacted to disappointing earnings reports and the prospects of higher interest rates.

The weighted LABJ Stock Index fell 3.5 percent to 163.12 for the trading week ended Aug. 16. Decliners outpaced gainers 115 to 43, with seven companies unchanged.

Among the largest decliners was MannKind Corp. which dropped 23 percent to $5.77. The Valencia biotech announced that key clinical trials of its inhalable insulin were successful, but the report also contained information about weight gain. An analyst attributed some of the loss to profit-taking.

Chatsworth microturbine maker Capstone Turbine Corp. dropped another 22 percent to $1.16 following a worse-than-expected second quarter report.

DTS Inc. fell 14 percent to $20.51. The Calabasas licenser of “surround sound” technology reported a larger second quarter loss and cut its full-year guidance.

Among the biggest gainers was National Technical Systems Inc., jumping 41 percent to $22.89. The Calabasas provider of engineering services agreed to be acquired by an affiliate of Aurora Capital Group for $267 million.

Tix Corp. rose 10 percent to $1.10. The Studio City provider of discount ticketing services reported better-than-expected second quarter results.