"Thank you for the bits of wisdom yesterday [Ed: Friday's Comment] from the Contrary Opinion Buttons. Here is one I came up with years ago: "It's OK to be wrong, it's not OK to stay wrong."

"On the HFT article that summarized Mr. Garrett's frustration with markets I would like to comment. I too had a rules based investment philosophy that had been back tested for decades and proven durable enough to build a business upon. Beginning with the vortex of the financial crisis (September 2008) and the policy interventions (short selling bans, etc.) those rules proved too rigid as the band of expected market movements broadened out considerably. My own confidence in my rules was violated. and like any virgin everything changes after the first time you are compelled to ignore the rules. Fast forward to that period last August that Mr. Garrett referred to and my result was similar though not as extreme, my response was to suspend my rules indefinitely and utilize Fullermoney. The point I am getting at is that Mr. Garrett's account of market activity is the first time I have seen anyone express what I had experienced: the post financial crisis market activity indeed seem to have a certain but diabolical pattern to it, replacing traditional patterns of expected movements. You had suspected HFT as the culprit, I had suspected policy interventions (QE etc.). Question: Since both HFT and policy interventions are here to stay how do you see the markets playing out over the next several years? Which is the bigger deal? The Garrett interview is a wakeup call.

"P.s. I am approaching my anniversary with FM and have quantifiable ways to measure the financial benefits your service has added to my business and portfolios. The results have been excellent. I have utilized an investment I could never have found without FM. I plan on renewing your service."

David Fuller's view Thanks for sharing your own wisdom, plus your continued interest in Fullermoney, and congratulations on seizing your opportunities over the last year. I trust that your attendance at TCS in London was helpful in that respect.

Investing is hard work, but worth the effort. We all have our rules and guidelines, which may serve us well for a while, but we should never forget that markets can do almost anything. In other words, markets are full of surprises. Generally, I think we are better prepared to deal with surprises if we keep an eye on the price charts, in the manner of a technical naturalist, observing the herd.

Re your interesting questions, policy interventions are not new, although we have certainly never seen this degree of QE since WW2. They are capable of producing trends which will sometimes persist for months. As such, I prefer to view policy interventions as a friendly guide, provided I pay attention to them. We only miss out if we rail against them or refuse to accept their influence once that becomes apparent in the price action.

High-frequency trading (HFT) is the latest and most significant evolution in computer trading, and it has become hugely influential. At best, I view it as the elephant in the room. At worst, it could become a terminator machine.

HFT's main influence is to increase volatility, often to the detriment of other market traders. I am concerned, and I think exchange officials and regulators should be particularly concerned about HFT's tendency to crowd out or drive away traditional investors.

As for markets over the next several years, I think we are still in a secular cycle of valuation contraction (see below).

(See also Friday's leader on HFT.)