Today was a slack day for the S&P/ASX 200 (INDEXASX: ^AXJO) (ASX: XJO), which fell 0.7% to 4,929 points.

A number of shares fell substantially further, and here’s why:

Monadelphous Group Limited (ASX: MND) fell 6% to $6.51 on no news as uncertainty continues to bounce around the values of miners and mining services stocks. Fellow services company Worleyparsons limited (ASX: WOR) also fell, losing 5% to $5.17 after rising 6% just yesterday. The entire industry has a big question mark hanging over it with low commodity prices encouraging miners to conserve cash rather than invest in new mines and construction. It is not suggested that Monadelphous or Worley are at imminent risk of going out of business, but the long period of mediocrity that has afflicted the sector appears unlikely to abate soon.

Monadelphous shares are down 34% in the past 12 months.

Ziptel Ltd (ASX: ZIP) lost 6% to $0.36 on no news, with uncertainty also affecting the company’s price in recent weeks. In this case, investors are unsure how Ziptel will raise funds for the next phase of its operations, considering it has $2.7 million in cash but outlaid $3.5 million over the past six months. On the plus side, the company has made substantial progress towards growing its market share and recently announced it has scaled up enough in order to commence monetisation of its product.

Ziptel shares are down 26% in the past 12 months.

Select Harvests Limited (ASX: SHV) dropped 6% to $4.01 after trading at $4.46 yesterday and falling as low as $3.73 earlier this week. Shares are volatile as a result of uncertainty in the market regarding the company’s earnings prospects. Record high almond prices have come down in recent months and investors – perhaps recalling the supply boom in the oil and iron ore industries – are wondering if this is symptomatic of booming supply and further impending price falls, despite management’s belief otherwise. Frankly I have no idea where almond prices are headed, but Select Harvests looks to be decent value for investors with an ability to look ‘through the cycle’.

Select Harvests shares are down 49% in the past 12 months.

Bank of Queensland Limited (ASX: BOQ) fell 5% to $10.90 after the lender raised its mortgage rates, despite the recent decision by the Reserve Bank of Australia to keep lending rates on hold. The bank lifted its rates by 0.12% for owner-occupiers and 0.25% for investor-only loans as a result of a rising cost of funding, and other banks are expected to follow suit in the coming weeks. Banks have come under pressure in recent times as a result of being forced to hold more capital, which effectively drags down their returns. Passing the costs on to customers is one of the ways to recover the extra costs, and is something we might see more of in the future.

Bank of Queensland shares are down 22% in the past 12 months.

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

Is a share-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 has no position in any stocks mentioned. 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.