'I'm extremely disappointed' by Royal Mail allocation
Royal Mail shares rose more than 38% to 456p at the start of conditional dealings on the London Stock Exchange.
The hugely oversubscribed sale was priced at 330p per share at the top of its expected range and valuing the near 500-year-old company at £3.3bn.
Richard Dawson applied for £6,000 worth of shares but received £750 worth.
He told BBC Radio 5 live's Breakfast: "I'm extremely disappointed by this and I think Vince Cable should have clawed back more than the 40 or 50% that was earmarked for institutional investors."