Take a look at some of the biggest movers in the premarket:

Tesla (TSLA) — Shares fell 1.2% in premarket trading after CEO Elon Musk challenged the United Auto Workers union to try and organize his company’s assembly plant in Fremont, California.

Sweetgreen (SG) — Sweetgreen shares soared 19.9% in premarket trading after the salad chain reported strong sales growth in its first quarterly report since going public in November. The company also posted widening losses.

Gap (GPS) — Shares surged 7% in premarket trading after the retailer reported a narrower-than-expected loss for the fourth quarter and issued strong earnings guidance. Gap posted a loss of 2 cents per share, versus the 14 cents forecast by Refinitiv analysts. Revenue also beat estimates.

Costco Wholesale (COST) — The retail stock retreated 2% after a better-than-expected quarterly report. Costco reported fiscal second-quarter earnings of $2.92 per share on revenue of $51.9 billion. Analysts surveyed by Refinitiv had expected earnings of $2.74 on revenue of $51.47 billion.

Marvell Technology (MRVL) — Shares dipped 2.3% despite a slight earnings beat. Marvell reported fourth-quarter earnings of 50 cents per share, excluding items, on revenue of $1.34 billion. Analysts had expected a profit of 48 cents per share on revenues of $1.32 billion, according to Refinitv.

Broadcom (AVGO) — The chip stock rose more than 3% premarket after Broadcom beat Wall Street expectations for its fiscal first quarter. The company reported adjusted earnings of $8.39 per share, while analysts surveyed by Refinitiv were looking for $8.08 per share. The firm’s second-quarter revenue guidance also came in above expectations.

Best Buy (BBY) — The retail stock dipped 2% in early morning trading after Raymond James downgraded Best Buy to market perform from outperform. “We are placing our stock recommendation in ‘sleep mode’ for now,” Raymond James said.