"Even under the unlikely scenario of Indo AirAsia (IAA) and Phil AirAsia (PAA) going bankrupt and 100 percent of the receivables owed by related parties are written off, our analysis shows that AirAsia will remain in a very solvent position," Jian Bo Gan, an analyst at CLSA, said in a note earlier this week.
While he noted the risk those receivables might become impaired, he added that not only was the risk not new, the current low oil prices could "forgive" the associates' competitive issues, making a full write-off unlikely. He kept a buy call, with a 3.10 ringgit target.
The shares' sharp drop spurred the carrier to file a statement to the Malaysia stock exchange midday Wednesday.
"Management would like to assure the investment community that the company has a solid footing, strong balance sheet, rich in assets and good business outlook," the statement said, citing its ability to boost its first quarter earnings despite the fallout from the crash of flight QZ8501. AirAsia is taking "strong corrective action" at IAA, expects it to break even by the end of the year and meet its payments to the parent company, it said. It expects PAA to reach profitability in the fourth quarter. It plans initial public offerings of both associates in 2017.
Not all analysts, however, are shrugging off the carrier's potential negatives. AllianceDBS cut its target price to 1.80 ringgit from 2.30 ringgit.
"AirAsia's depreciation policies seem aggressive vis-à-vis its peers," Tan Kee Hoong, an analyst at AllianceDBS, said in a note Tuesday, citing higher figures for aircraft's useful life and residual value. "This distorts earnings quality, and could lead to future losses when the aircraft are eventually disposed."
Tan is also concerned that AirAsia, which this week was named the world's best budget airline by Skytrax for its seventh straight year, may be propping up the bottomline with unsustainable interest income from amounts due from its associates and joint ventures. But even then, Tan is sticking with a Hold call on the stock.
AirAsia is just the latest in a string of companies targeted by extremely negative independent research reports. Often, other analysts note that these reports contain no new information, but the stocks generally drop anyway.
Singapore-listed Noble Group's shares are down as much as 40 percent from their February peak before research firm Iceberg Research published a series of anonymously written reports attacking the company's accounting practices. In 2012, Carson Block – the short-seller who founded research firm Muddy Waters – issued an attack on Olam; its share price is still down around 17 percent from its levels before that report.
Note: This story has been updated to include comments from GMT attributing the selling to long-only investors.
—By CNBC.Com's Leslie Shaffer; Follow her on Twitter @LeslieShaffer1