I agree.

When I started investing some time ago I stuck to the industry I was in, that being the Oil Service Industry for what is now Baker Hughes, a multi billion dollar world wide company.

I purchased stock in 5-10 service companies in the range of $10.00 to $40.00. I would buy 100 to 400 shares and when the stock price went up 10% or a little more, I would sell. I would also try and wait if close enough to a year for capital gain tax calculation. Being familiar with industry and the companies and what the economic outlook was if the short term future, I would buy back the same shares and hold again until it was wise to sell. I did this for a few years and never lost and gained on every stock and felt pretty good.

Then along came the high tech industry. I like many others jumped in on many stocks, did ok on about half and lost on the other half. Like you said, I got greedy and invested in some from the DD I did, but that fell short because I didn't know the industry wwell enough to manage my total portfolio.

I now own no tech stocks except EDIG and look at what that got me into, more than a decade of frustration. Give me a breakeven plus the time value of money on my investment and I'll call it a lesson learned.