Hackett Group (HCKT) shares nosedived 19.65% in pre-market trading on Wednesday, despite the company reporting better-than-expected first-quarter earnings. The dramatic sell-off appears to be driven by concerns over the company's underlying performance and the significant gap between its adjusted and reported earnings.

For the quarter ended March 31, Hackett Group reported adjusted earnings of $0.41 per share, slightly beating the analyst consensus of $0.40. Revenue increased by a modest 0.9% to $77.87 million, marginally surpassing expectations of $77.33 million. However, the company's reported earnings per share came in at just $0.11, revealing a substantial difference from the adjusted figure.

The stark contrast between Hackett Group's adjusted and reported earnings seems to have alarmed investors, potentially indicating underlying issues with the company's financial health. Additionally, the tepid revenue growth of less than 1% year-over-year suggests that the company may be struggling to expand its business in a challenging market environment. These factors, combined with the stock's already poor performance this year – having fallen 8.8% in the current quarter and 13.2% year-to-date before this earnings release – appear to have culminated in today's significant pre-market plunge as investors reassess the company's prospects.