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On Pivoting from a Concentrated to a Diversified Strategy and Position Sizing

There were two things on my mind recently:

  1. Living with a transition from a concentrated strategy to a more diversified strategy.
  2. Proper position sizing versus the risk of ruin.

I written my thoughts distilling position sizing, conviction, trying to be financially responsible before.

As a student of the game, it is always illuminating to hear about how money managers handle the finer details of investing.

I was reminded of two interviews Joel Greenblatt did that explains these two disciplines separately. Joel Greenblatt wrote a series of highly popular investment books, runs Gotham Capital and teaches investing at Columbia University.

Why did Joel transition from a Concentrated Investment Strategy to a much more Diversified Strategy?

Joel and his partner used to run a very concentrated NET-NET portfolio where 8-9 holdings will make up more than 80% of his portfolio. It is not uncommon for him to wake up one day and see some of his picks not working out. The portfolio will be down 20-30% due to that.

Around the 2000s, they tried and experimented with ways to buy not just cheap businesses but good and cheap businesses. This was due to the influence of Buffett on the quality factor.

By then, Joel have been teaching his students at Columbia University about investing in good and cheap companies.

From 2002 to 2003, they hired a programmer to do research on good and cheap companies. The first test they ran was a crude screen of 50% valuation and 50% return on tangible book value. The back-tested returns were fantastic.

They didn’t start out with trying to find the best way to make money but to test what they could achieve with some crude metrics (as explained above).

To Joel, this was a great way to share the implementation of the things he has been teaching his students.

This wasn’t the best thing to make money but was certaintly powerful enough for him.

It also set off a light bulb in his partner and his head.

If they apply their fundamental sophistication to the metrics, could they build a better model?

They managed to and eventually resumed taking outside capital again in 2009.

They discovered that if they developed a diversified long and short style strategy, it makes more money with less volatility than if they do a concentrated style strategy.

They chose to long 300-400 and short 300-400 from a basket of 3000 stocks in their diversified strategy. In contrast, a concentrated strategy entails doing the same but with 50 stocks.

The reason the concentrated strategy underperformed was that the concentrated strategy became much more volatile during certain periods such as 1999-2000 because the strategy also involves leverage.

Eventually, Joel felt that why he chose this strategy was a matter of preference. He was successful with both.

A diversified strategy allows him to work with a larger research team, follow more stocks and not subject his portfolio to the kind of drawdowns experienced with the concentrated portfolio.

Joel thinks that investors with certain temperament are more suited to certain strategies (not everyone can sleep well at night if its not uncommon for your portfolio to run 20-30% drawdowns in retirement)

Position Sizing is About Impairment Management

Joel was asked about his thoughts on position sizing and this is what he says.

Joel feels that position sizing is an important question.

Suppose you identified this great investment and you decide to put 2% of your capital into the position. If this position goes up 50-100%, you would have blown the position.

That could turned out to be your worst investment of all time because you should have had a 10-20% position and that would have moved the needle. (Joel mentioned that if that position was Tesla, which went up 10X, that 2% position would have moved the needle.)

Position sizing is the most important thing.

Being too timid about the few good ideas that come your way is the biggest mistake people make.

But of course, to take a large position, you have to be willing to be wrong, take big losses, to wait for that big position to know when it’s there.

The biggest positions he had are not his best ones, which is the positions that will go up 5X or 10X.

Often he is prioritizing controlling his risk than looking at the upsize when he is taking a big position.

In other words, Joel will size the position larger if he does not think he would lose much money. It’s not like the thing that’s going to pay 10 or 20 times.

Obviously, if you have a $10 stock, that’s sitting with $9 in cash and no debt, and they have a little business attached, we can buy a lot of that company, as long as we think the company won’t waste that cash. That kind of concentrated position may turn out to be a good asymmetric bet.

Joel explains that risk is not in an event such as COVID or 2008, when companies like Lehman goes down, a group of stocks can trade at any price.

His definition is whether a reasonable person can pick their spot to sell a stock over the next couple of years and won’t lose much money. They should think about what is the worse that could happen to that position. After that, they can then think about how much reward they could earn relative to this risk.

Joel then cite the example of buying a house.

A housing purchase often is the biggest purchase we can make. A house will be a large part of your net wealth and your salary, compared to a lot of other things.

Some people will be hesitent to purchase because they would think: “How much do I think I could lose at this investment?”

Instead of looking at the full lump sum, you can frame that you would be risking only 10-20% of the full value of the house.

If you frame it that way, you may be able to sleep better at night.


I think both interviews were helpful to me.

I could transition to another strategy, but I got to determine with enough confidence that the strategy will work just as well as if not better than the previous strategy.

Better may mean a better risk-adjusted return.

There are different degree of ruin for different stategy. For some investors, they do not understand the spectrum of volatility of the strategy they implement. So they either size too small (risk-averse) or too much (risk-seeking thinking things won’t go wrong or stonks only go up).

I might have overestimated the potential risk of ruin of my strategy way too much that it becomes detrimental to the portfolio. This is something that I got to re-evaluate and fine-tune.

I invested in a diversified portfolio of exchange-traded funds (ETF) and stocks listed in the US, Hong Kong and London.

My preferred broker to trade and custodize my investments is Interactive Brokers. Interactive Brokers allow you to trade in the US, UK, Europe, Singapore, Hong Kong and many other markets. Options as well. There are no minimum monthly charges, very low forex fees for currency exchange, very low commissions for various markets.

To find out more visit Interactive Brokers today.

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Sunday 6th of June 2021

This is an interesting post. I am having a good problem with my portfolio because it is getting bigger in term of overall value due to the bull market since last year. Currently, I have 14 companies. All of them will be considered as high-risk kind of "overvalued" growth stocks. I have been reflecting on shifting some money to dividend stocks. I think I am getting too old and mentally too occupied to persevere through a big drawdown again like last year. Wondering how many dividend stocks and position size for each to avoid loss. The whole mental shift is really big since I am more of a growth investor.


Monday 31st of May 2021

Hi Kyith

Thanks for the timely article. I have been thinking about my own investment journey.

Investing was hard to begin with, and has now become increasingly harder with government intervention (aka stimulus, interest rate cuts, china tech clampdown), HFT, AI bot-trading, leveraged bets, option trading and of course crypto.

Add meme stocks, Elon-type influencers driving stock prices up/down wildly ... I am wondering if Fair value exists anymore? During the worst of COVID, S&P can swing wildly from a -7% (triggering stock market circuit breaker) to a +7% by end of trading day. Who dare to buy/sell during these wild periods? You would get caught either way (just can't beat the bots).

Granted capital has probably been poorly allocated due to trillion-dollar stimulus and i/r cuts, I really wonder if Fair value will emerge when stimulus is finally withdrawn and i/r normalises? And even if it emerges, when will it happen (chances are the next crisis will happen long before FV emerges and the stimulus/interest rate merry-go-round happens one more time.)

If Fair value fails to emerge, then should we even be wasting time doing fundamental analysis on companies ... we might as well trade with the flow since FV no longer exists???

Just food for thought ... the last 18 months seems to indicate FV is becoming increasingly irrelevant...


Monday 31st of May 2021

@Kyith, can you share where and how your friends made money via value investing? Is it through SGX or HK/US/UK shares?

Also keen to find out (in case you know) how their performance pit against STI, S&P and HSI index performance? One can turn out to be a Bill Ackman or Bill Hwang :P

For me, while I made some money last year but lost almost half of it in recent 3 months when the tide changed (inflation scares, china tech clampdown, covid variant resurgence etc.).

What makes it worse is, whenever I sell a stock so that I can sleep better at night, that particular stock will bounce back to where it was before the drop. Bl00dy h3ll!

I fell short of STI, HSI and S&P index performance year to date (yes i know 5 months is not long enough to benchmark performance). I'm starting to question my own investing ability and investment psyche. Maybe I should just buy index ETFs and sleep soundly at night (and be happy with the 7-8% compounded returns over time).


Monday 31st of May 2021

Hi lalaman, I think the heavy influence of flow is a changing tide. However, there are still people that find that they can find portlets of space where they can still make money. value investing still works because there are some things trading below the intrinsic value and value does get realized. I have friends continue to do that and still make decent money from that.


Monday 31st of May 2021

When entire stock market goes down 30+% in 1 month & ALL sentiment/cyclical indicators are off-the-charts doomsday, no need to think about fair value. Just BTFD.

No need to bet the farm if you're scared. 33% or 50% of your cash is still good. Minimum at least put 25% of your cash to work in such scenario.

If you're wrong & doomsday happens, cash AND GOLD is worthless anyway --- guns, ammunition, parangs, muscle, gangs, water, food, 1st aid supplies are the most important.

If you're right, you get to add long term holdings at bargain prices.


Sunday 30th of May 2021

A recent article about concentration & turnover from a former fund manager.

His conclusion is that it depends on the investment style & type of companies.


Monday 31st of May 2021

Free registration.


Monday 31st of May 2021

Thanks Sinkie for sharing this. It is behind paywall though.

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