Sealed Products

beatthebookienet

Sealed Body is 4 characters too short.

Bookworm105

as you infer, the trading rules take precedence over CGT but "proving" the intent was to trade is another matter if only a few sales take place many years apart 

it is no different to any other form of "collecting"

liability to income tax rather than CGT would be based on what is called the "badges of trade"
BIM20205 - Meaning of trade: badges of trade: summary - HMRC internal manual - GOV.UK

you are of course expected to be honest when doing your self assessment, if bought with the expectation of trading then you are, were, and will be, a trader

beatthebookienet

So in conclusion
£100 put into a 5% cash ISA would take 15 years to double, no tax
£100 put into the S&P500 at an average return of 10% would take 8 years to double, no tax
With a £100 sealed product you take the risk that it would double in value in a shorter timeframe and then pay 20% tax on the profit. There are of course the costs and risks with storage and selling

So the sealed product (even with 20% tax) may still be a feasible way to diversify in investing on both a small and large scale

On a smaller scale the trading allowance could be used to sell up to £1000 of sealed product per year without paying tax

Bookworm105

S&P500 would be "investing" and therefore liable to CGT for a UK tax resident (if outside an ISA) 

trading is trading, its risk and reward is very different to a tax free savings vehicle, but you are correct the trading allowance is available if your realised profit margin is low enough.

(bear in mind in the very extreme case it is possible to be subject to income tax rather than CGT when buying and selling stocks/shares if you are classed as a trader rather than investor)