The Los Angeles Business Journal’s index of the largest local public companies rose slightly for the week. The weighted LABJ index rose 1 percent to close at 232, with gainers outpacing losers 83 to 67. Six companies closed the week unchanged.

Among stocks trading above a dollar, Carson online retailer U.S. Auto Parts Network Inc. was one of the week’s leading gainers. Shares rose 28 percent to close at $2.04 on Friday after Mehran Nia, its co-founder and former chief executive, wrote a letter calling on the company’s board to explore a sale.

El Segundo postage seller Stamps.com also had a good week. Shares rose 18 percent to close at $72.94 after the company reported strong first-quarter earnings, beating analysts’ estimates.

Spark Networks Inc., the company behind special-interest matchmaking sites such as ChristianMingle.com and JDate.com, was among the week’s losing stocks. Shares fell 20 percent to close the week at $3.17 after the company reported lower than expected earnings.