The Luton-based carrier has benefited from improved revenues trends and benign weather, which reduced levels of de-icing and disruption.
Easyjet now expects losses between £55 million and £65 million in the six months to March 31, compared with guidance in January of £70 million to £90 million and losses of £61 million a year ago.
Shares, which have more than doubled since the start of 2013, were up by another 5% today.
Chief executive Carolyn McCall said the performance showed the company's structural advantage in the European short-haul market against both established carriers and low-cost competition.
She added: "Our strategy of offering our customers low fares to great destinations with friendly service and a focus on cost control ensures that we can continue to deliver sustainable growth and returns for our shareholders."
Revenues per seat are expected to be 1.5% higher in the six months, driven by allocated seating, digital initiatives and longer average flights.
Costs per seat growth is likely to be around 0.5%, which is better than the guidance of 1.5% issued at the end of January.
Profits in the last financial year to September 30 jumped 51% to £478 million, with ongoing efforts to attract more business travellers meaning it flew more than 60 million passengers for the first time.