The whole point of investing is to buy low and sell high. I think we all agree with that.
If not, you are reading the wrong publication.
Pound cost averaging is all about the benefits of snapping up more of an investment when it is cheaper, and less when it is more expensive.
Institutional investors forever rebalance their portfolios to ensure that a stock that has massively outperformed does not dominate, and to benefit from the uplift they get.
These are all fundamentals.
But oh, should retail investors want to have a conversation about selling their holdings or get more information about taking profits, it is like they have caught the plague.
They suddenly become the untouchables; fear of contagion is rife.
Heaven forbid retail investors should behave in as ruthless a manner as institutions.
The rise and the democratisation of investment, largely driven by technological advances, has been one of the great achievements of financial services in the past two decades.
Yet, despite improvements, retail investors are in an underprivileged world.
They do not have the same access to information as the institutions or financial advisers.
They can not see Morningstar data, or details from the rating agencies. They also do not make a profit no matter what.
Fund managers keep their 1 per cent or so every year no matter how their fund performs; they do not have to worry so much about taking profit.
But also, there is no requirement on them to reveal what they do with the money.
One who I spoke to recently reminded me how they had quietly sold out of Woodford very early on, though of course we, the ordinary public, did not know that.
Retail investors just are not blessed with the same access to information.
There is a peculiar logic at play here. Everyone wants retail investors to behave rationally, but no one wants to give them the information to do so.
So they are left without information, and more prone to acting irrationally.
It is almost like the industry wants them to be the necessary idiots. And so ordinary investors taking profits are demonised.
That is why it is so hard to get companies to publicise when they make changes to their best-buy lists, it is the fear of creating a market.
We are 12 years into a bull run; some investment houses have enjoyed spectacular runs and made fans of so many investors.
It is inevitable that at some point these funds will run out of steam, and the market will stutter.