So much for summer doldrums. The broad averages have tacked on nearly 10 percent since June, with no hint that the torrid pace will cool with the official start of autumn later in the week. But isn’t that always the case before a new market paradigm surfaces, often with the subtlety of electroshock therapy?  Indeed, Mr. Market has historically been at his most wrenching come October, and it is perhaps only waxing expectations of this in recent years that has tempered his inclination to mete out punishment to the unwary. The Dow Industrials, playing catch-up with indices skewed toward the digital economy, look eager to test January’s record high at 26616. The requisite 462-point rally could happen as early as this week, and while it would appear that the Indoos will have little trouble getting there, there’s no reason to be complacent, much less ebullient, when the headlines trumpet the news.