** Shares of Sam Altman-backed nuclear startup Oklo OKLO.N rise 3.8% to $52.20 premarket

** Seaport Research Partners upgrades stock to "buy" from "neutral" with PT of $71

** PT represents premium of 41.2% to stock's last close

** OKLO has ability to self-source its nuclear fuel given sufficient capital, regulatory approval and access to Spent Nuclear Fuel, brokerage says

** Seaport adds that after period of intensive capital investment in reactors and fuel, OKLO will generate enough discretionary cash flow by 2032 to increasingly self-fund its enterprise growth

** 8 of 10 brokerages rate stock "buy" or higher and two rate it "hold"; their median PT is $55 - LSEG data

** As of last close, stock has gained nearly 137% YTD

(Reporting by Vallari Srivastava in Bengaluru)

((Srivastava.Vallari@thomsonreuters.com;))