MannKind Corp. was once again a leading gainer this week. Shares for the Valencia biopharmaceutical developer of therapeutic products for diseases such as diabetes and cancer rose 17 percent to close at $2.11 on Thursday.

Shares for CytRx Corp., a biopharmaceutical research and development oncology company based in Brentwood, rose 15 percent to close at $2.46.

Chatsworth oil and natural gas producer California Resources Corp. was the week’s losing stock. Shares fell 30 percent to close at $1.24.

Ritter Pharmaceuticals Inc., producers of therapeutics for gastrointestinal diseases, was down in the market for the second week in a row. Shares for the Century City firm fell 20 percent to close the week at $1.12.