We discussed 100-24 in MBS 4.5's this AM in the following context.

"This is a classic example of inflection and/or pivot point.  Technically speaking, we talk time to time about "one man's floor being another man's ceiling."  The suggestion is that if a price level was "tested" and proved resistant to breakthrough, that once that level was finally broken, it's more likely to have ongoing technical significance and resistance to breakthrough coming from the other direction, aka "SUPPORT."

And prices certainly had that chance to approach from the other direction as the 4.5 fell about 5 ticks from it's highs of the day.  But 100-24 stepped up and indeed filled that support role.  Remember, these pivot points aren't hard and fast rules, but amount to an "odds increase" to a minor extent as well as an indication that a previous trend is shifting.  But the odds are in our favor today apparently, and the current trend of strength remains intact after the most serious test of 100-24 support seen since this AM.

Now, we're getting to that point where decisions must be made regarding your overnight positions.  Just as pertinent as the 100-24 support is the 100-30 resistance overhead that's been visited three times so far today.  It's likely that this range will be broken tomorrow, even if the reasons have more to do with it's narrowness than expected organic price cues.  That said, tomorrow is our biggest day of data this week.  Prices will likely respond to a certain extent to the AM data.  And then again surrounding the auction announcements.

Simply put, there's always going to be a risk to the overnight float, and it's more a matter of hedge ratio and your personal risk tolerances.  Hence, the Gut-Flop.  Just be aware of the dual nature of tomorrows significant events.  One round in the AM.  Another round later in the AM at 1100AM.  Later still, there's the less volatility-inspiring fed balance sheet and money supply at 430pm.  To whatever extent the AM data leaves you in floating shape, there's a chance you can ride that wave and lock as necessary if the reaction to auction announcements proves to be negative.  Again though, that is dependent on prices holding current levels through AM data.  Response to that data may be more muted than it otherwise would be in the absence of auctions. 

No lock v. float bias here, just a discussion on what to be aware of for tomorrow.  Also be aware that stocks don't like losing these days and may take any opportunity to rally back and erase today's loss.