California-based EV manufacturer Tesla, whose sky-high share value has long been a hot topic of discussion among pundits, has just crossed a ridiculous threshold, exceeding $1,000 per share during normal trading on Wednesday. That was enough to push the automaker's total market cap past $180 billion, the company inching closer to Japanese heavyweight Toyota - one of the world's largest automakers by global sales volume, and the most valuable auto company with a market cap of more than $210 billion.

For reference, Ford has a market cap of around $27 billion, while GM has a cap of about $41 billion. Tesla is, somehow or another, worth the equivalent of more than four GMs.

But how did Tesla get to this point? The most likely driver behind the EV company's rally on Wednesday is a memo sent to employees declaring it "time to go all out" on putting the Tesla Semi into volume production. The memo was a direct response to the fanfare surrounding the initial public offering of Nikola Corp. - a rival electrified vehicle startup that's working on a hydrogen-fuel-cell tractor unit that could compete directly with Tesla's Semi.

Interestingly, Musk's memo never actually provided a target timeline for bringing the Semi to market, nor did it provide much in the way of new, solid information - just that the company wants to accelerate development, and that battery and powertrain production will take place at Giga Nevada. Eventually.

Also buoying share prices further, Tesla has recently begun international deliveries of the Tesla Model Y, with Canada being the first country outside of the US to receive the brand's latest product, despite the fact that production is still behind schedule after recent factory shutdowns.

Adding further fuel to the fire behind Tesla's share value, there seems to be some credence behind the rumors that the much-vaunted 'million-mile battery' will officially be in production before the end of 2020. While China will be the first market to receive the new tech, it could be game-changing in the grand scheme of things, more than doubling the lifespan of Tesla's current battery tech and making the prospect of long-term EV ownership, including the secondhand market, extremely viable.