In afternoon trade, the S&P/ASX 200 Index (ASX: XJO) is pushing higher again. At the time of writing, the benchmark index is up 0.4% to 7,681.2 points.

Four ASX shares that are rising more than most today are listed below. Here's why they are storming higher:

The Healthco Healthcare and Wellness REIT share price is up 5% to $1.18. This morning, this healthcare and wellness property company announced a $50 million on-market share buyback. Head of Real Estate, Sid Sharma, said: "The buy-back demonstrates our conviction in HCW's value proposition and long-term growth fundamentals. We believe the current unit price presents an attractive opportunity to gain exposure to a high-quality portfolio of critical healthcare infrastructure at a significant discount to NTA."

The Medadvisor share price is up 15% to 31 cents. This has been driven by the pharmacy-focused patient engagement solutions company's quarterly update. Medadvisor reported a 42.4% increase in operating revenue to $24.2 million. This has lifted its year to date revenue to $99.8 million. Management notes that this is more than it recorded in FY 2023 with one quarter still to come. Gross profit grew 48.5% during the quarter to $15.3 million, bringing its year to date gross profit to $58.7 million. This is up 20% over the prior corresponding period.

The Ramsay Health Care share price is up 2.5% to $52.35. This appears to be due to media speculation that Wesfarmers Ltd (ASX: WES) could be running the rule over the private hospital operator. It would certainly be a sizeable purchase for Wesfarmers. Ramsay Health Care currently has a market capitalisation of approximately $12 billion. Neither company has responded to the media speculation.

The Tamboran Resources share price is up 3% to 17 cents. This morning, this natural gas company announced a binding long-term gas sales agreement. This will see Tamboran Resources supply the Northern Territory Government with 40 TJ per day from the proposed Shenandoah South Pilot Project for an initial term of nine years. Tamboran is targeting a final investment decision on the proposed project in mid-2024, with first production planned by the first half of 2026. The company's managing director and CEO, Joel Riddle, commented: "This is a transformational development for Tamboran and our partners, after ten years of hard work and more than A$500 million invested in Beetaloo exploration and appraisal activities."