The picture and the price are two different clocks

A stream sits beside a market that is not on the same clock. The price refreshes many times over in the seconds the picture takes to arrive, so a reader looking at both is looking at a current number and an old picture, and the gap is the number worth remembering.

Desk spec

price refresh: 0.2 s
picture lag: 12.0 s
gap: 11.8 s
price moves first: 60x

the pictureA live picture is a licensed broadcast shown beside a market, not a window onto the event. It has an owner, a territory and a cost, and only 96 of 300 events in the month carry one.

the two clocksThe event happens at 0.0 s, the price refreshes at 0.2 s and the picture arrives at 12.0 s, so the number beside the picture is 11.8 seconds newer than the picture it sits beside.

the one sourceThree things describe an event - the picture, the data feed and the official result - and only the official result settles a bet. The picture looked decisive in 96 of 100 disputes and settled none of them.

Direct answer

The market beside a stream refreshes in about 0.2 seconds while the picture takes 12.0 seconds to arrive, so the number is 11.8 seconds newer than the picture and can move sixty times before the picture catches up. That gap is not an advantage to be exploited; it is why a reader should never treat a delayed picture as a reason to bet faster.

Two clocks, one screen

A price is a stream of bytes and a picture is a stream of video, and the two travel on paths of different lengths. The price path is short: a few numbers from a trading system. The video path is long: capture, encode, package, deliver and buffer. Placed side by side they look simultaneous, and they are not.

Sample C - the two clocks measured from the event
What the reader sees	Reaches the screen	Is behind the event by	Where it comes from
the price	0.2 s	0.2 s	a trading system pushing numbers
the picture	12.0 s	12.0 s	capture, encode, package, deliver, buffer
the reader, reacting	13.4 s	13.4 s	the picture plus the reader's own delay
three clocks	-	0.2 / 12.0 / 13.4 s	one screen, three different moments

sample C - the gap between the picture and the price price reaches the screen = 0.2 s after the event picture reaches the screen = 12.0 s after the event gap = 12.0 - 0.2 = 11.8 s the price refreshes 12.0 / 0.2 = 60 times in the time the picture takes to arrive once and if the reader takes 1.4 s to react, the reaction lands 13.2 s behind the price: the price can have moved 66 times (13.4 / 0.2) by the moment the reader acts.

Why a delayed picture is not a fast market

The tempting conclusion from a delayed picture is that the reader sees the past and can act on it, and the tempting conclusion is wrong. What the reader sees has already been priced, and the market has moved on by an amount that grows with every second of delay. The picture is a way to follow the shape of an event, not a way to be early to a number.

sample C - what the delay does to a price, and what it does not do if the price moves by 0.01 every 0.2 s, then over one picture lag it moves 12.0 / 0.2 = 60 ticks, i.e. 60 x 0.01 = 0.60 on a 2.00 price a reader acting at 13.4 s is 67 ticks, or 0.67, behind the event but the delay is symmetric: the same 60 ticks stand between the reader and everyone else watching the same delayed picture, so 0 of the 60 ticks is an edge and 60 of 60 belong to the market, which is cycle 19's subject (value against the closing line) and not this desk's.

Check the two clocks before you trust the screen

Does the price move before the picture, which shows they are not synchronised?
Is the market in-play, where the gap matters, or pre-event, where it hardly does?
Has the picture frozen while the price kept moving, which widens the gap silently?
Is the delay the same on every device, or worse on the one you are watching?
Would the same bet make sense with no picture at all, which is the only version that is safe?

The picture and the price are two different clocks

Two clocks, one screen

Why a delayed picture is not a fast market

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