Today two interesting, if not defining financial milestones were achieved by technology giants Google and Apple. Apple fell under the $400 billion dollar mark in normal trading hours, and Google passed the $300 billion notch [Data: Google Finance].

The two shifts over big-number-moments comes during the day in which Google held its I/O event keynote, that covered a great many of its product categories. The markets sent Google up, and Apple down. Other market cohorts such as Microsoft had moderate days, with that firm rising 0.8% in normal trading.

Apple, once by far the most valuable technology company, has fallen sharply from former highs. Its 52 week high is $705. The stock current trades at $424. That decline came over the course of the last nine months.

Though the two firm’s valuations are narrowing, that doesn’t meant that Google’s earnings are set to overtake Apple’s. Apple trades at a valuation that is roughly a third higher of Google’s, and its PE ratio is just 37% as large. So, for every dollar of profit, Google is valued more richly; this indicates that the market expects Google to grow more quickly.

After a record string of quarters that became year’s, Apple’s revenue for the most recent quarter declined on a year-over-year basis. The slowing growth of the firm has knocked nine-figures off of its valuation.

Google had a good day today, not just in the market, but also at its own developer conference. Applause was strong throughout, and the demonstrated tech was impressive.