What’s most surprising, looking at CRH’s first-half results and share price reaction yesterday, is how little the company has been impacted by Covid-19.  Four weeks after the pandemic first hit the markets, CRH shares had fallen 49 per cent. €12 billion of value had been wiped off the company.  What’s happened since would have been difficult to predict in mid-March. Shares in CRH are up 91 per cent in the last five months.  Why is that? It’s not much to do with the company or its management. What’s happened since then is that the overall market has bounced back from…