Ayear ago today, a lucky investor could have bought the Hong Kong-traded shares of China CNR and CSR Corp, then the country’s two dominant train makers, for less than HK$6.10 each and watched them rise and rise on rumours of an impending merger.

Six months later, the two companies confirmed that they would indeed become one, with CSR offering 1.1 shares — by then worth HK$8.05 — for every CNR share. When the new company, renamed CRRC Corp, began trading on June 8, its shares flirted with HK$15.70 before falling back during the past week. Barclays analysts have a price target of HK$17 for the new stock.

Between them, these two lumbering rolling stock manufacturers have more than 170,000 employees and dozens of disparate subsidiaries spread across the country. Why are so many investors rushing to get aboard?