This chart shows massive breakout in stocks versus bonds

Michael Nagle | Bloomberg | Getty Images

We're back to bonds' pain and stocks' gain again today, as the "reflation rotation" wheel turns and momentum serves as its own reward.

After a pause, the upward push in Treasury yields resumed - simply the necessary obverse of the increased inflation and growth hopes, and swelling risk appetites, embedded in the stock-market action. Here's a look at relative strength of stocks versus bonds:

Source: Bespoke

The comeback in stocks has been sharp and sudden. But after such a prolonged stretch when bonds held the advantage, might there be more to go?

Estimates vary widely on what 10-year Treasury level would present more friction for stocks, starting at 2.75 percent (Goldman Sachs) and heading up toward 4 percent. One thing sure, stocks are not cheap in aggregate and the "typical" stock is more expensive than the indexes, so any setback in the growth story or sudden inflation/Fed scare into the New Year and buyer's remorse could set in quickly.

Here's what else I'm watching going into closing bell:

Overbought market

A result of this relentless bid is an overbought market, judging by many standards ranging from gut feeling to eyeballing the steepness of the Russell 2000 rally to statistical gauges of buying extremes. One day this week more than 18 percent of S&P 500 stocks hit a new 52-week high, the most since December 2014. And, as I've been noting, sentiment has turned bullish according to plenty of indicators, though we probably are not yet all the way to dangerous euphoria. Overbought and "over-bullish" don't mean "sell everything." They mean we should expect a pause and maybe a sharp selloff is some decent excuse comes along – or that any big upside from here might well be retraced. Another quite-strong day for corporate bonds mitigates most concerns, for now, that any quick equity pullback would be the start of something badly damaging. 

Beware round numbers

Would it be nice and cute if the Dow hit 20,000 next week just as the Fed was ready to give a rate hike the market is begging for and the public expresses renewed optimism based on an administration not yet in office – and then stocks stopped right there and maybe reversed? Sure it would. And round numbers are often another reason for a pause. But markets stray from the tidy story lines more often than they follow them.  

Finding another spot

There's plenty of bifurcation among sectors, and it's been fairly impressive the way groups have taken turns leading the market on a given day, with some of the defensive areas up nicely today as the cyclicals and financials take a breather. This seems to show money not looking to exit the market entirely but finding another spot – there's that lack of sellers' urgency again. Are they waiting to see if capital-gains taxes go down, or pushing gains into a new tax year regardless? Do they want out of bonds more than they want to cash in on equity gains? A lot of volume was traded in last winter's panic, which means a lot of investors bought and are sitting on huge percentage gains. Maybe they want to hold for a full year into January/February to convert them into long-term capital gains to ease the tax bite? Maybe, hard to say. Unlike my fourth grader, the market is not required to explain its answers or show its work. 

Trump trade?

Media stocks have been notable out-performers the past week – a once-lagging and disdained segment of consumer discretionary whose stocks had become cheap, as I wrote in a CNBC Pro column in September. Technical strategists are starting to take note of the refreshed momentum here. Not a pure Trump trade, but the incoming administration is assumed to be more friendly toward traditional media over digital upstarts. Here's an ETF that tracks the group (and also some digital media giants such as Alphabet):
PowerShares Dynamic Media Portfolio (PBS), 1 month

"Sure, the stocks are down a lot, but there's so much uncertainty about the pricing of the companies' products that it's hard to bet on a comeback." That was said this time last year about energy stocks, and arguably could apply now to discarded specialty-pharma names. The likes of MylanPerrigo,Allergan and Teva are up more than 1 percent today, perhaps as some take a flyer on the idea that most scary news has already been priced in?