Wyckoff trading method, page-190

An upbar or down bar is determined from the previous close to the current close, in whatever timeframe you are working.

Volume - is seen as 'Effort' of 'Force'.
Volume is an important measurement of Market Activity.
And at times of high activity (or high volume), volume can be seen as making an 'Effort' or having 'Force' upon price.
And low volume (or activity) can suggest a lack of effort or force on price.

This is because VSA/Wyckoff is built around the three laws
"Supply and Demand"
"Cause and Effect"
"Effort Vs Result"


Weakness, when it is seen, will be initially be seen on a down bar
Strength, when it is seen, will be initially be seen on an upbar.
(I have changed these statements slightly from the original statements, to make them more correct in my opinion)
These two comments are strongly pushed during educational VSA webinars, and they can confuse many, especially when getting started.
What they are saying is not that every decent upbar is weak (or that every decent downbar is strong).

--But that in a strong market (for instance), when serious weakness does eventually enter a market (weakness which will possibly change the overall trend), it will be initially on an upbar.
--And Obviously the reverse is also true..... in a weak market, when serious strength does eventually enter the market (strength which will possibly change the overall trend), it will be initially on an downbar.

And so whenever a widespread upbar is encountered (often on a good news announcement), particularly one with quite high volume, be wary (or aware) that although the bar may look really strong and full of buying, it may be a sign of potential weakness, or possibly the beginning of weakness entering the market (further price action is used to measure this potential weakness or strength).
When this occurs, the high volume can only be present if someone is happy to be selling, satisfying all of the demand which has been generated.
This is because larger holders cannot easily just sell their holdings, so when they choose to begin reducing their holdings. They generally need a positive event (such as a good news announcement) to increase demand in the market substantially, and then they can sell into the strong demand that the announcement encourages.
At times these events can be strung out for multiple days (if the news is good enough). Where these larger holders may even 'keep the price up' by buying some more when necessary, if demand begins to wane a little, attempting to give the market confidence the higher prices are justified, and encouraging further buying (finance news services may also be used to foment further interest, especially in larger cap stocks, or particularly interesting news).

I may add to this further in the future.....

cheers