The Dow Jones Industrial Average hit the 40,000 mark for the first time on Thursday, about 19 months after it last topped 30,000. Since last surpassing 30,000 on October 17, 2022, no Dow stock has had a bigger percentage gain than Caterpillar – which has nearly doubled in price. But when it came to the biggest impact on the Dow during that time frame, it was Microsoft that led the way – pushing the index up more than 1,200 points. Remember that the Dow is a price-weighted index that gives higher priced stocks more influence. Microsoft, which ended Wednesday at $423.08, has a higher share price than Caterpillar, which last closed at $360.04. The road to 40,000 is also very heavy. Five of the Dow’s 30 stocks – Microsoft, Caterpillar, Goldman Sachs, Salesforce and American Express – have accounted for half of the index’s overall gain in its journey from 30,000. Only one stock – Johnson & Johnson – is definitely down since the last time the Dow surpassed 30,000.