Source: Sharecast
The broker said the London-listed firm’s stock had underperformed since it announced a near £7bn rights issue at last week’s full-year results.
But it continued: "We see the funding underpinning the new £60bn capex plan. Our updated full-year 2025 earnings per share are 14% lower, but we see 7% 2025-2029 compound annual growth rate, with balance sheet headroom for additional growth capex.
"Regulatory updates due in the next six-to-12 months would improve visibility."
Adding that the blue chip appeared "cheap", Jefferies concluded: "We reiterate our ‘buy’ rating with a new price target of 1,150p, implying 40% total shareholder return."
The previous price target was 1,330p.
As at 1015 BST, shares in National Grid were up 2% at 863.52p.
National Grid said last week that it would use funds raised in the £6.8bn rights issue to upgrade its networks, to enable them to cope with the switch to low-carbon energy in both the US and UK.
It called the planned £60bn outlay, which is due to be spent between 2025 and 2020, a "significant step up" in its investment plans.