Once again, I fired up the Way, Way, Wayback Machine:
On April 27, 2014, Standard & Poor's gave Tesla's credit an unsolicited junk bond rating of B-, or "highly speculative", with its analysts' comments including the categorization of Tesla as a "niche" automaker, and cast a shadow on the company's long-term prospects. Not uncoincidentally, but I found in my files a note that at that time, TSLA's market cap was $17.8 billion (has it risen since then, anyone?).
Here is my post from that day, including some wording from S&P that jarred me then, as it should all now:
Summary: Oh man, have I been waiting a long, Long, LONG time for this month. That dish that's best served cold - learn it, if you don't know that already.