The S&P/ASX 200 (Index: ^AXJO) (ASX: XJO) has dropped 2.7% in the past month, mostly driven by falls in the big four banks.
The Commonwealth Bank of Australia (ASX: CBA) share price has plunged 6%, Westpac Banking Corp (ASX: WBC) has seen its share price smashed down more than 11%, National Australia Bank Ltd (ASX: NAB) is down 9% and Australia and New Zealand Banking Group (ASX: ANZ) share price also down more than 9% since May 8, 2017. That is mostly to do with the new bank levy, which will hit the bank's earnings and likely force cuts to their dividends.
But those falls aren't the worst in the index. These five companies have all seen their share prices fall by 20% or more in the past month.
The Aconex Ltd (ASX: ACX) share price has dropped 20% from $4.92 to the current price of around $3.94. The construction software company has been targeted by short-sellers hoping the share price would go down, after reporting disappointing first-half results, and directors selling shares – which is never a good look.
Galaxy Resources Limited (ASX: GXY) has seen its share price fall more than 21% from $2.48 to $1.95 currently. The lithium miner is ramping up production at its Mt Cattlin project, including making three shipments of product to customers so far this year. But it seems some investors have doubts about the company actually meeting the goals that it has set itself so far this year and have been selling out.
Nanosonics Ltd. (ASX: NAN) share price has fallen more than 25% from $3.35 a month ago, to the current price of $2.51. The healthcare supplies company hasn't released any official news since March 1, so maybe investors have become impatient – which may be a perfect opportunity for Foolish investors to jump in.
Asaleo Care Ltd (ASX: AHY) has also seen its share price sink more than 25%, from $1.91 to $1.43 currently. The company saw its Chief Financial Officer resign in mid-May, and that the CEO had sold more than 1 million shares in the company. Like Aconex above, shareholders dislike it when directors sell their shares in the company – unless it comes with an acceptable explanation.
Sirtex Medical Limited (ASX: SRX) has suffered the biggest fall in the index over the past month, with the share price sinking 27% from $16.17 to trade at $11.80 today. The company – which produces radioactive spheres to help treat liver cancer – has had a terrible run, from slower sales and profit downgrades, to the CEO being fired for inappropriate trading in the company's shares.
Foolish takeaway
There may yet be hope for these companies to turn around their share price performance. Director selling may not be the negative signal investors assume, and patient investors can take advantage of opportunities when share prices are depressed for reasons that may have no impact on the company's financial performance.