Yes. Its called 'dilution.'

The stock price typically drops when more stock is issued into the float (publicly traded stock). By selling off their remaining stake of roughly 9.3 million shares, it effectively devalues the holdings of existing stockholders.

So, why would they do this? Well, they're most likely just cashing out and taking profits. However, dilution can occur when a company may have interest from a potential buyer. If Oaktree feels that NK is overvalued from a market cap perspective, they could sell their remaining stock. By selling off their remaining stake, it will lower the stock price and possibly create an opportunity for a buyer to offer a premium for NK stock. NK's market cap is roughly $1.5 billion.

This happened when AirTran was sold to Southwest (Guadalupe Holdings). Credit Suisse quietly issued AirTran stock into the float. The stock price dropped. Southwest came in and offered AirTran's stockholders a premium for their stock. A sale was commenced.

The opposite occurs when a company 'buys back' their own stock. It removes stock from the float, inflating the value of existing holdings causing the stock price to rise. This tactic could be used when a company wants to secure more control, or make their company more expensive to purchase, or to prevent a hostile takeover scenario.

Ownership can influence their own company's stock price simply by manipulating the float...either by selling off large chunks of stock (dilution), or by repurchasing their own company's shares.