ITA Wealth Management

You are here: Home / Beginning Investors / How Many Assets Should I Hold In My Portfolio?

How Many Assets Should I Hold In My Portfolio?

By

This question has been asked in a number of Blog Posts and we pussy-foot around it because there really is no definitive answer. On the one hand we need enough to give us an adequate level of diversification (whatever that means) to reduce volatility (risk) while keeping our commissions, management costs and fees to a minimum.

We maybe start out by thinking of diversification as “more is better”, progress to thinking of it in terms of different asset classes (Equities, Bonds, REITS, Commodities, Metals,…etc), then, recognizing that even this does not necessarily guarantee that we are diversified, we may look closer at correlations and  “clustering”.

Also, we all have different investment styles – Strategic Asset Allocation (SAA) requires us to make discretionary decisions as to which assets to hold and the allocation to be made to each asset – Portfolio Optimization reduces the discretionary limits to a degree and calculates “recommended” allocations to different assets/asset classes – momentum tends to dominate diversification decisions to some extent and leave the discretionary decisions to allocation weightings.

I recently found the following figure in one of Gary Antonacci’s articles on “Key Momentum Factors”.

Momentum - Number of Assets

This shows that portfolio volatility drops rapidly (exponentially) as we increase the number of assets from 1-5, but that adding more assets beyond this level has little impact. On the other side of the equation, returns (based on momentum) tend to drop in a more linear manner – thus there will be an optimal balance in terms of return/risk – this provides a good explanation for the excellent performance of the Feynman Max4 Portfolio.

Let me play Devil’s Advocate and suggest that (from a “scientific” point-of-view) it may not be advantageous to construct portfolios containing more than 4 or 5 assets (remembering that these assets are already “diversified” ETFs).

This should be good for discussion – please don’t “shoot the messenger”, remember I’m playing Devil’s Advocate – disclosure – I don’t (presently) have any portfolios with so few assets.

(Visited 242 times, 1 visits today)

Comments

  1. David,

    Let me ask the first question to this post. Did Antonacci mention if his graph refers to individual stocks or to index funds such as ETFs?

    Lowell

    • Lowell,

      Antonacci uses ETFs – I believe almost exclusively – at least in his articles.

      David

  2. ITA Readers: There is an excellent book that parallels the above argument. “How A Second Grader Beats Wall Street” by Allan S. Roth is all about a portfolio made up of three index funds. They are: VTSMX, VGTSX, and VBMFX. These three funds cover the entire U.S. Equities market, total international equities market, and total bond market.

    Lowell

    • David / Lowell,

      I’m an ex-Boglehead and used the simple 3 fund portfolio VTSMX, VGTSX, and VBMFX. It did fine, but got clobbered in ’08 and that’s when I decided against ‘buy and hold’ and started searching for alternatives. The BH mantra is “Tune out the noise” and “Stay the course”. Sorry, but just can’t do that, simple as it sounds.

      Re: Diversification – Used to be that a 60/40 port the 40% bonds were your main diversifier. Not any longer however. So bonds are pretty much useless (to me) at this point in time. That leaves US vs Int’l equities, REIT’s, commodities etc.

      I then read a couple of Sy Harding books. He has a portfolio of exactly ONE ETF; DIA. He goes ‘all in’ in mid-Oct and all out (cash) end of April. I’ve done some backtesting with this seasonal phenomenon and find, oddly enough, that his theory / practice has worked for him and others.

      I then read ‘The IVY Portfolio” which uses 5 ETFS and monitors a 200 day moving average.

      So, I’m in transit…. looking for the best approach to get me OUT of the market before a major fall. As for getting in, right now, things are SO overvalued that it’s hard to pull the trigger on anything. Wife and I are sitting on a huge pile of cash in our 401k’s / ROTH’s waiting for a good time to move a sizeable amount back into action.

      Interesting times for investing for sure.

      • Charles,

        On the original blog I think I might have a few entries on Sy Harding’s model. He now adds or uses a MACD overlay to his seasonal model. If you search for MACD on the original blog you will find how Gerald Appel’s MACD is calculated. Appel published these results back around 1979 and I have his original booklet on this subject. The booklet even includes instructions how to program the TI-81 to come with the results. Now we just use the Internet. (g)

        Lowell

      • Mitch,

        That’s why I spent a lot of time on Part 6 of the Feynman Study and tried to stress the importance of Risk Management. Although my personal preference is to use the SHY Filter, a MA is good too – just do something, no matter how simple, to insure the Buy and Hold. See Part 6.2.2 of the Feynman Study for an example of effectiveness with a “Buy and Hold” (although not quite at this point) Portfolio.

        If an Investor (probably not you) just wants to Buy and Hold a portfolio of assets without selling anything and doesn’t have time to monitor the portfolio, it might still be advisable to buy an annual insurance policy (Put Option) for portfolio protection. It will reduce returns but at least it will avoid devastating drawdowns.

        David

      • Mitch,

        I’m doing some work on “Seasonality” right now – but it’s more focused on my Options Trading than on my (retirement) investments – just another way I, personally, bring diversification into the equation.

        David

  3. Lowell:
    As I read Antonacci, including the paper you reference, and his other papers, he is talking about ETFs.
    Dick

    • Charles,

      Thanks for the links. I watched these videos some weeks ago and found them quite interesting.

      As for editing your comment, you should see an Edit option just to the right of the time stamp near the top of your comment. See if it is available to you as it is for me.

      Lowell

Most Popular Posts

General Investment News

Portfolios coming up for review are:  Euclid, Bethe, and Millikan.  Non-scheduled portfolios may be reviewed.  If you are a new user, check the posts you missed. Links to Random Posts are found in the lower right-hand footer or just to the right of what you are now reading.  Most popular posts are found in the lower left-hand footer.

Random Posts

Do NOT follow this link or you will be banned from the site!
%d bloggers like this: