Phil Fisher was the ‘grandfather’ of growth stock investing and many decades ago, he wrote a book called ‘Common Stocks and Uncommon Profits’.
Legendary investors such as Buffett, Lynch and Anthony Bolton (Fidelity manager from the UK) have often stated that this book taught them about growth stock investing.
In this book, Phil Fisher clearly wrote that for MINIMUM diversification, an enterprising investor must have exposure to at least 5 large cap/institutional grade stocks from DIFFERENT industries (max. 20% exposure to one company).
He went on to state that if one’s portfolio is comprised of upcoming/younger companies, then it must have exposure to at least 10 such stocks from DIFFERENT industries (max. 10% exposure to one company).
Finally, he also wrote that if one’s portfolio is comprised of unprofitable/speculative companies, then it must have at least 20 stocks from DIFFERENT industries (max. 5% exposure to one company).
ON VALUATIONS…
Stocks represent claims on the long-term cash flows of operating businesses and the higher the price you pay for those cash flows, the lower the subsequent investment return over the full stock market/business cycle.
Sure, stocks can be bid up to dizzying heights during a raging bull-market but history has shown that when the music does stop, the market darlings of a bull market are the hardest hit and they lose 50-80% of their value in a matter of months.
At least this is how things have played out since the beginning of time and if SaaS turns out to be a truly novel industry which is totally immune to economic and monetary conditions, then it will be a first.
Having said all of the above, I’d like to clarify that I’m not anti-Saas (I have positions in DOCU, SHOP, TWLO and ZUO) but this sub-sector represents perhaps 20% of my total portfolio and the rest of my cash is invested in dominant/high growth companies from other sectors (e commerce marketplaces, fintech, payments, medical equipment, video gaming, audio and video streaming etc).
Best,
GM