What are some of your biggest investing mistakes?

It is far better to learn from other people’s investment mistakes than learning from your own. I’ll start:

  1. Influenced by the share price movement
    Changing my narrative to justify the reason for holding i.e why a holding is still undervalued after +100% or why a holding is deeply undervalued after a -80% decline despite changes to the fundamental.

  2. No idea what I’m buying
    If you don’t know what you’re getting yourself into, chances are you won’t have a clue when to get out. The latter is more important. As Nassim Taleb used to say 'Better to take risks you can measure than measuring the risk you’re taking." Bought GTN at $2.06 in 2016 right after IPO, went up to $3.90 (+89%) in 4 months feeling I knew it all along (when all I know was they do radio ads while reporting traffic conditions from the helicopter). Currently trading at $0.48.

  3. Not sticking to my rule
    When I bought Magellan (MFG) during COVID (avg. cost base $32+), I made a selling rule that I’ll sell if Hamish Douglass quit the company (because I wasn’t sure if MFG’s outstanding record is because of individual brilliance or its culture or something else like macro tailwinds). He did. And I didn’t sell for whatever self-justified reasons. Currently trading at $8.53

  1. Not having any spare capital to invest at the start of Covid, being scared to sell/swap existing investments!
  2. Investing in too many funds, resulting in a complex mix of overlapping investments and making it almost impossible to see the wood for the trees
  3. Investing in specialised sectors that I have a particular interest (but not much knowledge of), for example semiconductors, logistics and infrastructure funds.
  4. Handing over capital to an online investment management company that manages the portfolio on your behalf. Negative returns over several years and the added bonus of them investing tiny amounts in offshore funds which resulted in complex UK tax return submissions :frowning: