Amazon to Invest in Retraining for Workers (NASDAQ:AMZN) on Thursday unveiled plans to retrain a third of its U.S. workforce — or 100,000 workers — by 2025 to help its employees move into more advanced jobs or find new careers.

The retail and tech giant intends to expand its existing training programs and introduce new ones. The training will be voluntary, and most of the programs are free.

A company statement said programs will help workers "access training to move into highly skilled technical and non- technical roles across the company’s corporate offices, tech hubs, fulfillment centers, retail stores, and transportation network, or pursue career paths outside of Amazon."

Amazon’s retraining programs will include: Amazon Technical Academy, which equips non-technical employees with the skills to transition into software engineering careers; Associate2Tech, which trains fulfillment center associates to move into technical roles; Machine Learning University, which offers employees with tech backgrounds the opportunity to access machine learning skills; Amazon Career Choice, a pre-paid tuition program designed to train fulfillment center associates in high-demand occupations of their choice.

The story, which first broke in the Wall Street Journal, said the planned program is among the biggest corporate retraining initiatives ever announced, at a cost of roughly $7,000 per worker, or $700 million.

Amazon shares are up 34% this year and are among the top performers in the five-year run by the S&P 500 to 3,000 from 2,000.

Those shares started Thursday up $4.40 to $2,021.82