It has taken Wall Street a long time to warm to Google’s second act.

This week, however, stock market investors have finally thrown aside some of their wariness. By pushing the search company’s shares to their first record high in almost five years, they delivered a vote of confidence in the new, more diversified advertising business that has become the basis for Google’s latest surge of growth – while also giving an implicit thumbs-down to Facebook, whose short-term chances of putting Google in the shade, at least in business terms, have receded sharply.