Four publicly listed dry bulk shipping companies will join an elite few other shipping companies as part of a broad index measuring the value of the US stock market.

But the annual rebalancing of the equity index also saw a number of offshore companies get dropped, including John Fredriksen's Seadrill. 

The Russell 3000 Index added Eagle Bulk Shipping, Genco Shipping & Trading, Navios Maritime Holdings, and Safe Bulkers as part of its annual index reconstitution issued on Friday. 

The Russell 3000, which is used to benchmark investor performance, aims to capture 99% of US equity market value. It looks at factors including where a company is incorporated, where its shares trade, its market value and its share float to determine if a company should be included in the US index. 

Membership in the Russell 3000 Index remains in place for one year. The Russell index is published by FTSE Russell, which is owned by the London Stock Exchange Group. Russell indexes are use to benchmark $8.4 trillion in equities. 

Frontline, Scorpio Bulkers, DHT Holdings, Gener8 Maritime, and GasLog are currently members of the Russell 3000. 

But the offshore sector got widely demoted as the Russell 3000 rebalancing saw the elimination of a number of offshore names, including Hornbeck Offshore Services, Tidewater, and Seadrill.