I know I am reviled as a  cash hoarding market pessimist,a contrarian etc etc (and I have been called a lot of worse etc etc's) but that is imo a very homogeneous (therefor risky) strategy,including the possible risk of dying of boredom.
(Although investing in stocks because you enjoy it or find it interesting is considered a Presbyterian sin around here,I know)
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If that was my portfolio I would sell the gains to date.
You know what they say about money in the bank ....:)