Step beyond margin of safety

Margin of safety is the much vaunted investment tool of value investors, and by value investors I mean all sensible long-term investors. Margin of safety is a great concept, but is it the best tool for investment selection, risk management and portfolio optimisation?

Michael Mauboussin argues it is in this excellent 2001 paper.

Investors should base the magnitude of their investments on the size of the margin of safety.

Mauboussin’s Ruminations on Risk is a brilliant paper. I mostly agree with him, but want to share an even better investment tool we can easily use.  But before we get to that, let’s play a game.

Game on

Imagine you have two investment options. Investment A has a margin of safety of 12 percent, while Investment B has a MoS of 8 percent. Which would you invest in?

Probably neither, right? So for the sake of the game imagine you must invest in either A or B.

I’m going to hazard a guess you opted for A. Its MoS is 50 percent greater than B and for some of you that return may even be above your hurdle rate.  Investment A is the logical choice if you use MoS as you primary investment selection tool.

Let’s keep exactly the same investments, but throw my preferred investment selection, risk management and portfolio optimisation tool into the mix. Let’s look at the return/risk profile of these investments.

risk/return ratio

The current price of both A and B is $5. Investment A has an 80 percent chance of being profitable, that is a 60 percent chance of 20 percent upside and a 20 percent probability of a juicy 60 percent profit. Conversely Investment B has a mere 20 percent of being 20% profitable.

Remember, I haven’t changed the game, the respective margins of safety for A & B are still 12 percent and 8 percent.

Are you still happy with your investment decision? As a reminder, A has a 12 percent MoS and an 80 percent chance of being profitable, whereas B has an 8 percent MoS and a mere 20 percent chance of profitability.

Think risk

If you’re still opting for A, then perhaps the following sentence which encapsulates my investment philosophy will help change your focus slightly. Focus on the downside, and the upside will take care of itself. (Hat tip to Mark Sellers.)

The downside for A is 60 percent, whereas B has a comparatively modest 20 percent potential loss. Hopefully, that changes your investment decision. For me, focusing on the risk rather than the return has led to better investment decisions, and I’m confident it will for you too.

Investment B is the better investment choice, despite having both a lower margin of safety and lower probability of profit. I know some of you won’t be convinced and may even believe the higher probability weighted MoS for A means that over time successive investments in A will result in higher overall returns.

The pain of asymmetry

We’ll you’d be right, except for the asymmetry of returns. For those not familiar with the asymmetry of returns, all it means is that identical percent gains and losses are not the same, e.g. it takes a 100 percent gain to make up for a 50 percent loss. Losses hurt more and not just psychologically.

This asymmetry results in B having the higher probable return after a number of iterations. For example if we start with $5 then after ten iterations B will have grown to $8.20 while A will only have grown to $6.10.

If you’re using a probability weighted margin of safety you’re already way ahead of most dart throwing investors, but it may be time to take another step on your investing journey. Adding the return/risk ratio to your tool kit helps you focus on the downside and will improve your risk management.

My hurdle rate is not a percent return, it’s a return/risk ratio of three. For every dollar risked I want a potential payoff of three dollars. Investment B meets that criterion, whereas A has return/risk ratio of 1:1. See what a huge difference the return/risk ratio makes? It’s like pulling back a veil to see the real picture.

As I said in this post, using a risk return framework forces me to consider multiple outcomes and to look forward. It provides a rationale mechanism to overcome the noise of fear and greed. Most importantly, it forces me to consider what could go wrong.

The return/risk ratio is also my portfolio optimisation tool of choice. The higher the ratio the larger my investment.   As I said 3:1 is my hurdle, I may invest a small portion of funds in companies meeting that hurdle, I start getting excited with ratios over five. I invest a lot when the ratio is over seven, as I did when I was pounding the table on Telstra in early 2011 – back when everyone else was calling Telstra a dog. Currently Telstra does not meet my hurdle rate, but as I’ve sold most of our holding and admit to being slightly addicted to its dividend, I continue to hold a small weighting.

Part Two – Putting the return/risk ratio into practice

Once you start regularly using the return/risk ratio it makes investment decisions easier.

What’s the probability and size of the downside? What’s the probability and size of the upside?

This same frame work should be used for both prospective and perhaps more importantly to current positions.  After all it’s only what you own that can hurt you. Saying that, I admit to not rigorously applying it existing holding, although I really should.

Imagine you’re a reasonably smart investor and followed my recommendations of investing in Integrated Research (ASX: IRI) at around $0.45. Hold on, I think I’ve written about this before. Yes here you go.

When I sold, Integrated Research was up 265 percent since my recommendation in the first edition of Motley Fool Share Advisor. IR was also up a market obliterating 300 percent since I’d recommended it as one of TMF Australia’s radar stocks.

Like me, you may have found IR was close to 3 times larger a position in your portfolio than originally intended. That’s a nice problem to have, but it is still an issue that requires thought. For example if you bought a 5 percent position, IR was now over 13 percent of your portfolio.

Above $1.30 IR was significantly overvalued. So why hold 3 times your normal position in an overvalued company? That would be stupid right? But hey if you see it differently please let me know in the comments below.

Here’s how someone summarised IR on Hot Copper:

However, it tells the story: 1st article when IRI had earnings of 4.5c, share price under 40 cents, dividend 4 cents, and cash. Relatively low risk.

Now, 2012 earning 5.4 cents, SP $1.20+, dividend 5 cents, still has cash.

Company obviously in a sound position, however value … ? One would have to say the “easy” money has been made.

I like that thinking. It’s simple, value focused and based on tangible information.

At the current price of $1.24 my analysis suggests a possible downside of $0.40. Yes, you should always work out the risk fist, remember focus on the risk and the return will take care of itself. So I only need to answer one question, is a $1.20 upside probable?

Can IR double in price from here? I see virtually no chance of that.

IR has grown revenues at 3.5 percent a year over the last five years, while earnings per share have grown at a miserly rate of 1 percent. The growth rate has been slightly higher over the shorter time-frames, but still nothing to get excited about.

While I respect the excellent management team and think Mark Brayan justly deserved the IT Executive of the year award for his excellent strategy and execution, there simply is no sound investment case that can be made for IR at the current price.

Mr Brayan sensibly diversified IR’s revenue stream due to the sword of Damocles hanging over the company – the huge risk in HP Non-stop infrastructure revenue collapsing. He has added a few more hairs to the sword, but make no mistake, software is a cyclical business and if, or more likely when, those infrastructure revenues go into terminal decline the slowing growth of unified communications and payments are unlikely to stop investors being cut.

Back to the point

Anyway, I’m getting away from the point of this article, which is that a return/risk framework is a superior investing tool than margin of safety. It conveys more information and focuses on both the risk and return, whereas margin of safety tends to focus the mind on returns. My returns have improved since adopting the return/risk ratio and my losses have shrunk. For me it is the ultimate risk management and portfolio optimisation tool.

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6 comments

  • Hi Dean, I didn’t quite get the calculation. Tell me if I am incorrect here: A has 60% probability of 20% upside, 20% probability of 60% upside and 20% probability of 60% downside. B has 20% probability of what postive payoff and 80% probability of 20% loss ? I am not sure if you specified the upside for B.

  • Hi Sean, 20% profitable for B. I’d deleted that, as the text had too many numbers and it’s shown in the chart. But I’ve now put the 20% back in. Best, Dean P.S. Good luck on your house search

  • Hi Dean, I have decided to read this again, after mulling about risk and the Kelly criterion for some time. I related your example to the choice between the arithmetic and geometric mean. If you compute the usual arithmetic mean of A, you get $1.12, while you get $1.08, which makes A seemingly look like a better choice. This is when one thinks of a “one-off” bet with capital. Under the geometric mean, things change, however, with A being $1.02, while B being $1.05. Under this measure, B is the better choice, intuitively, it has less “spread” between the upside and downside. The latter is a better choice of comparison if one is holding the investment for a long period, while parlaying bets. I guess your return/risk ratio is a nice heuristic that ties in with Kelly’s criterion: bet more when the odds favours you. Thus, margin of safety is just half the story. Great article!

  • If it was significantly overvalued at $1.30, wouldn’t it have been overvalued at, say, $1.10-$1.20? If holding above $1.30 would be stupid, would that make holding at $1.10 a little bit silly?

    Also, how do you (or perhaps, others) calculate a MOS?

    Cheers.

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