Anyone who ploughed through all 370,000 words of General Motors’ registration document, some four-fifths as long as War and Peace, is none the wiser about how big GM’s offering will be or how much each shareholder will sell. But securities regulators frown on historical fiction, so a quite useful snapshot of the carmaker, warts and all, can be gleaned by the intrepid reader.

GM clearly is viable enough and, more to the point, big enough – set to be around the 35th largest company in the S&P 500 – that fund managers will subscribe even if the global economy cools before the expected offering date in November. One non-economic consideration that may influence the price they pay is “overhang” or latent share supply. This goes beyond the question of how many tranches of the outstanding 500m shares will be sold in subsequent offerings and how much political pressure to make taxpayers whole might hasten this.

Even before Wednesday’s announcement of a dilutive mandatory convertible preferred share offering, potential buyers knew that existing warrants could boost GM’s share count by nearly 22 per cent. A union healthcare trust may reap another 15.2m shares on top of the 87.5m it already owns if GM’s market value is above $64bn, as expected. Given the union’s rapid dumping of Fordwarrants and desire to diversify, it is a likely seller. Warrants for a far larger block of shares due to bondholders will also almost certainly be in the money, piling nearly 94m shares on top of the 50m they already are due to receive.