Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of electric-car maker Tesla (NASDAQ:TSLA) are being driven higher following reports that it delivered 6,900 vehicles in the fourth quarter.

So what: The final tally of 6,900 deliveries represents 25% more than the third quarter and over 15% more than the amount Tesla guided for. In its third-quarter-earnings release, the company stated that it expects to deliver "slightly under 6,000" vehicles.

Now what: This announcement follows Tesla's trend of under-promising and over-delivering, in this case literally. An extra 900 vehicles priced around $100,000 each adds over $90 million in extra revenue for the company in the fourth quarter. 

With Tesla forecasting 25% gross profit margins, it's reasonable to expect at least an extra $22.5 million in gross profit, most (if not all) of which should find its way to the bottom line, potentially adding $0.18 per share.

Analysts forecast earnings per share of $0.15, so it is very possible that earnings may top this estimate by more than double.

Tesla last quarter guided for 21,500 total vehicles delivered for 2013, and the company plans for a production run of 40,000 vehicles by end of 2014. Now, the actual total for 2013 is 22,400, and the run rate for the fourth quarter should be 27,600, so it would seem that the target for 40,000 deliveries in 2014 is off to a good start, especially considering that it isn't until the second quarter of 2014 that Tesla expects the larger boost from production capacity.

Look for analysts to upgrade their estimates, and for Tesla to offer even higher estimates, for the first quarter of 2014 and the full year. While even $0.30 earnings per share for the fourth quarter would still suggest that Tesla is richly valued, both the top and bottom lines stand a chance of accelerating, and it could be only a matter of time before earnings begin to catch up with valuation. Tesla may not be for everybody on the long side, but cautious Fools should avoid betting against Tesla.