Elon Musk fired a warning shot across the bow of short sellers Sunday.

Tesla Inc.'s (TSLA) CEO didn't mince words when he sent this tweet about shorts Sunday afternoon:

They have about three weeks before their short position explodes

— Elon Musk (@elonmusk) June 17, 2018

Tesla remains the most shorted stock on the U.S. market, with more than 30.8% of Tesla's float currently held short at last count. That's more than $12.82 billion in short interest, according to the numbers from S3 Partners.

Simply put, being short Tesla is a crowded trade right now - so much so that very few shares of Tesla are available to short at current level.

Meanwhile, Tesla has been in rally-mode this month, up more than 24% since the calendar flipped to June, as Tesla has taken out key technical breakout levels. Now Musk is signaling that shorts could be in store for more pain.

What's he talking about?

Chances are it'll be Tesla's second-quarter 2018 Vehicle Production and Deliveries release, which is likely to be published shortly after the quarter ends late June. A big part of the short thesis for Tesla is built around the firm's ability to meet production expectations for the Model 3. A positive surprise from Tesla could have a big impact on the stock's price, particularly in light of the momentum shares have shown the last couple of weeks.

An internal email obtained by Electrek indicates that Tesla is currently at a run rate of more than 3,500 units per week on its Model 3 production line. Musk told employees that he will be at the Fremont factory "almost 24/7" to resolve the final bottlenecks to reaching Tesla's 5,000 unit-a-week goal by the end of June.

Things are about to get very interesting in the Tesla trade.

Meanwhile, shares are shaking off broad selling Monday, up more than 2.6% as of this writing, as shares continue their momentum run.

More upside is still the high-probability technical trade for Tesla.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.

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