Discovery, Palantir rise; Nikola, Ameren fall

Stocks that moved heavily or traded substantially Wednesday: Discovery, Palantir rise; Nikola, Ameren fall

NEW YORK — Stocks that moved heavily or traded substantially Wednesday:

Discovery, up $1.05 to $28.26

Oprah Winfrey sold most of her stake in OWN to the media company, news outlets reported.

Nikola, down $1.80 to $15.03

The electric vehicle maker said it was discontinuing its collaboration with Republic Services on developing garbage trucks.

Palantir Technologies, up 65 cents to $28.69

The data and software company signed a new two-year contract with the United Kingdom’s National Health Service.

Cloudera, up 36 cents to $15

The provider of data management services announced a new credit facility that will be used to fund stock repurchases.

Ambac Financial, up 38 cents to $16.83

The company agreed to buy a majority stake in Xchange Benefits, which provides international insurance underwriting,

Marathon Oil, up 50 cents to $6.81

Energy companies rose more than the rest of the market as crude oil prices climbed.

Humana, up $16.65 to $405.09

The health insurance company announced an accelerated stock buyback program.

Ameren, down 83 cents to $75.72

Ameren Missouri, a subsidiary of the St. Louis-based company, bought its first wind farm.