Nio Inc (NYSE:NIO) stock bottomed at a record low of $4.90 in late March, but has since come off this level. Citigroup thinks the worst is over for the electric auto stock, with analyst Jeff Chung upgrading the shares to "buy" from "hold." And while he cut his NIO price target to $6.80 from $7.20, this still is a 28% premium to last night's close.

BofA-Merrill Lynch also chimed in on Nio stock, lifting its rating to "neutral" from "underperform." Ming Hsun Lee -- a top-rated NIO analyst, according to Refinitiv data -- cited expectations for growing sales in the second quarter following the launch of the company's six-seater ES8.

Nevertheless, NIO shares are down 0.3% at $5.29, feeling the heat as rival Tesla (TSLA) sells off on weak first-quarter deliveries. Options bears are making a rare appearance, too. Specifically, the January 2020 4-strike put is most active today, with almost 11,000 contracts traded. The bulk of these put options have been bought to open, meaning traders are targeting new lows by early next year.

More broadly, it's been call buyers that have been targeting Nio stock amid its bounce from all-time lows. At the International Securities Exchange (ISE), Chicago Board Options Exchange (CBOE), and NASDAQ OMX PHLX (PHLX), speculators have bought to open 84,060 calls over the last 10 days, compared to 10,339 puts.

The bulk of this action has centered at the weekly 4/5 6-strike and April 6 calls, where data from the major options exchanges confirms significant buy-to-open activity. In this case, call buyers expect NIO shares to break out above $6 by the respective expiration dates of tomorrow, April 5, and Thursday, April 18.

Given how heavily shorted NIO stock is, it's possible some of the activity at these out-of-the-money strikes could be a result of shorts initiating an options hedge against any additional upside risk. Short interest on Nio rose nearly 31% in the two most recent reporting periods to 67.6 million shares, representing more than two-fifths of the equity's available float.