Today was a pretty ordinary day for the S&P/ASX 200 (INDEXASX: ^AXJO) (ASX: XJO), which lost 0.25% to 5,144 points at the time of writing.

A number of shares were absolutely hammered however, and here’s why:

Silex Systems Ltd (ASX: SLX) plunged 47% to $0.34 today after the company announced that its licensee and commercialisation partners were pulling out of a joint venture intended to further develop Silex’s nameplate uranium enrichment technology. The news appears likely to leave management scrambling to find additional funding partners, and the company has announced it may fund calendar year 2016’s expenses from its own pocket, at a cost of up to $10 million. Although Silex has approximately $50 million in the bank, today’s announcement clearly increased the risk associated with the company.

Silex shares are down 48% in the past 12 months.

Qantas Airways Limited (ASX: QAN) lost 11% to $3.61 after management released an operating update revealing ongoing business pressures thanks to reduced demand for both domestic and international flights. The news was sufficient to hammer the share price, despite media reports that oil prices were likely to stay low after a conglomerate of oil producing nations failed to reach an agreement to boost prices – which would ordinarily have sent shares higher. Now that much of the tailwind of lower oil prices is already factored into Qantas’ share price, investors may want to consider whether the airline industry is still an attractive place to park your cash.

Qantas shares are up 2% in the past 12 months.

McGrath Ltd (ASX: MEA), a very recent Initial Public Offering (IPO), saw almost a third of its value evaporate as shares fell 31% to $0.90 following an announcement. Management declared that there would be a significant downgrade in revenues and earnings for the current financial year, as a result of a significant decline in Sydney property listings. Investors are likely now asking themselves if conditions in Sydney could be set to worsen.

McGrath shares are down 54% since listing.

Senex Energy Ltd (ASX: SXY) crashed 11% to $0.26 after oil markets failed to reach an agreement to raise prices in Doha over the weekend. Senex’s falls were complemented by declines of 6% at Santos Ltd (ASX: STO), and 5% at both Origin Energy Limited (ASX: ORG), and Oil Search Limited (ASX: OSH). In this writer’s opinion it was folly to believe that all involved nations would successfully collaborate to raise prices, although the fact that the meeting was even held suggests the degree to which low prices are undesirable. While I haven’t made any further investments in oil since prices crashed, a couple of companies look interesting today.

Senex shares are down 35% in the past 12 months.

As the ASX flirts with 5,000, some experts are predicting a market crash...

Is a market crash REALLY coming? Get our analysts' exclusive inside take now, in The Motley Fool's newly updated report, "What to Do When the Sharemarket Crashes" -- including expert tips on how to protect YOUR portfolio.

What are you waiting for? Just click here now for your free copy!

HOT OFF THE PRESSES: Motley Fool’s #1 Dividend Pick for 2017!

With its shares up 155% in just the last five years, this ‘under the radar’ consumer favourite is both a hot growth stock AND our expert’s #1 dividend pick for 2017. Now we’re pulling back the curtain for you... And all you have to do to discover the name, code and a full analysis is enter your email below!

Simply enter your email now to receive your copy of our brand-new FREE report, “The Motley Fool’s Top Dividend Stock for 2017.”

By clicking this button, you agree to our Terms of Service and Privacy Policy. We will use your email address only to keep you informed about updates to our website and about other products and services we think might interest you. You can unsubscribe from Take Stock at anytime. Please refer to our https://www.fool.com.au/financial-services-guide">Financial Services Guide (FSG) for more information.

Motley Fool contributor Sean O'Neill owns shares of Senex Energy Limited. The Motley Fool Australia has no position in any of the stocks mentioned. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy. This article contains general investment advice only (under AFSL 400691). Authorised by Bruce Jackson.