The S&P/ASX 200 Index (ASX: XJO) is back on form and pushing higher on Monday. In afternoon trade, the benchmark index is up 0.4% to 8,345.1 points.

Four ASX shares that have failed to follow the market higher today are listed below. Here's why they are falling:

Australian Ethical Investment Ltd (ASX: AEF)

The Australian Ethical share price is down 2.5% to $5.17. This follows the release of the fund manager's quarterly update. Investors have been selling shares despite Australian Ethical continuing to see growth in funds under management (FUM) with another quarter of positive net flows and investment performance. This led to the company reaching the milestone of $13 billion FUM during the quarter. Managing Director, John McMurdo, said: "I'm delighted that our continued commitment to our growth strategy has enabled us to achieve new milestones over the period, with $13.26 billion in FUM reflecting 27% growth for the financial year to date." It seems that some investors were expecting even stronger growth from the fund manager.

PYC Therapeutics Ltd (ASX: PYC)

The PYC Therapeutics share price is down 3.5% to $1.12. This morning, this clinical-stage biotechnology company revealed that the US Food and Drug Administration (FDA) has granted it a Rare Pediatric Disease (RPD) designation for its VP-001 drug development program. This program aims to address the underlying cause of a blinding eye disease in childhood known as Retinitis Pigmentosa type 11 (RP11). This development may have already been priced in by the market.

Resolute Mining Ltd (ASX: RSG)

The Resolute Mining share price is down over 3% to 39.2 cents. This appears to have been driven by a pullback in the gold price on Friday night. It isn't just Resolute Mining that is falling today. A number of gold miners are starting the week in the red. As a result, the S&P/ASX All Ords Gold index is down over 1% at the time of writing.

Star Entertainment Group Ltd (ASX: SGR)

The Star Entertainment share price is down almost 6% to 13.2 cents. Investors have been selling this struggling casino and resorts operator's shares following the release of its quarterly update. Star revealed that revenue was down 15% quarter on quarter in the second quarter to $299 million. And while EBITDA was negative at $8 million for the second quarter excluding significant items, this was an improvement on the $18 million EBITDA loss it recorded in the first quarter.