Shares in bookmaker William Hill (LSE: WMH) have slumped by 13% today after it released a profit warning. It states that two main factors have combined to deliver a weaker-than-expected online performance. The first is an acceleration in the number of time-outs and automatic self-exclusions in recent weeks, which are expected to reduce online profit by between £20m and £25m this year.

The second is regarding gross win margins, which are 1.9% below expectations in the period, at 6.2%. They’ve been affected by European football results and also by the worst Cheltenham results in recent history. Taking these factors into account, William Hill’s operating profit for the full year is now expected to be between £260m and £280m. Due to this downward revision, investor sentiment has been hit hard.

While William Hill has a number of strategic priorities that could improve its outlook and much of its business is trading relatively well, it seems prudent to avoid buying it at the present time. Prior to today’s update, its valuation appeared to be rather unappealing and news of a downgrade to profitability expectations makes it even less so. Therefore, there seem to be far better places to invest for the long term.

Too many risks

Also enduring a challenging period is oil producer Genel Energy (LSE: GENL). Although this week saw a further payment made for oil production, Genel continues to offer an unappealing risk/reward profile. That’s because it has four main threats to its long-term future, with its location being a major risk due to its proximity to the politically unstable Northern Iraq/Kurdistan region. This is likely to keep investor sentiment pegged-back, while the uncertainty of payment from the regional government (and the slow repayment of outstanding debtors) puts pressure on Genel’s financial outlook.

Add to this the potential for a falling oil price as well as the $1bn in asset writedowns set to take place this year and Genel seems to be worth avoiding right now. That’s despite it having a relatively enticing asset base and sound strategy, with its risks simply outweighing the potential rewards.

Because it’s worth it

Meanwhile, many investors may question whether Reckitt Benckiser (LSE: RB) can continue its excellent share price performance. The consumer goods company has posted a rise in its valuation of 14% in the last six months, but now trades on a price-to-earnings (P/E) ratio of 24.5. That’s high relative to the FTSE 100, which has a P/E ratio of around 13.

Although Reckitt Benckiser’s upward rerating potential may be somewhat limited, the company has superb long-term growth prospects. That’s because it has a stable of top-notch brands and with consumer wealth levels across the emerging world gradually rising, Reckitt Benckiser has huge scope to increase its bottom line over the coming years. And with its earnings being very stable, it could prove to be a rewarding defensive play during times of uncertainty too. As such, it appears to be a buy rather than a sell for long-term investors.

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Peter Stephens has no position in any shares mentioned. The Motley Fool UK has recommended Reckitt Benckiser. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.