I don't think it's irrational yet... we have a ways to go before it's 'irrational'. Irrational is when the P/E's are above 100 and the stock can still move $5-$10 a day up.
On the other hand, after the last 'irrational exuberance', people are a lot more cautious this time around.
I've gotten rid of a few longs today, and I hit the tops on a few, which is nice. That's not to say they moved all that much, but some gain is better than any loss later. I'm holding on to my most irrational tech tho.
IF, and it's a big IF, the whole 3rd year of Presidency, no recession, stocks are going up thing comes about, and we get some irrationality... it will be tech that's irrational as usual.
Gold has been down a few days. You may want to look at some of those too. Sooner or later, it's going to move.