Previous day and week highs and lows — the lines yesterday and last week leave behind

In plain words

Yesterday's highest and lowest Bitcoin price, and last week's highest and lowest. Everyone sees the same four numbers. So many traders park orders at them, and when price reaches one of these lines, something tends to happen.

This article is about four lines:

• PDH (Previous Day High) — yesterday's highest price
• PDL (Previous Day Low) — yesterday's lowest price
• PWH (Previous Week High) — last week's highest price
• PWL (Previous Week Low) — last week's lowest price

The highs and lows in the earlier articles move depending on a rule (how many candles to look at). These four are set by the calendar. There is nothing to compute, which makes them the simplest levels — and the most widely watched.

The concept

When does a "day" start and end?

Where you cut the day changes yesterday's high. Our chart cuts it at midnight UTC — 9 a.m. in Korea. So on our chart "yesterday" runs from 9 a.m. yesterday to 9 a.m. today (Korean time), the same span as one daily candle.

A week starts on Monday 00:00 UTC, which is Monday 9 a.m. in Korea. "Last week" runs from last Monday 9 a.m. to this Monday 9 a.m.

The line starts at "yesterday" and runs to the right edge

Each line starts at the first candle of its day (week) and runs to the right edge of the chart. Where a line starts tells you which day (week) it belongs to. When the day changes, "yesterday" changes and the lines move to new levels.

A real Bitcoin 1-hour chart from October 2025 (dates and times in Korean time, like the chart axis). The "now" of this example is the last candle, 8 a.m. on 20 October. It is not yet 9 a.m., so "today" is the day that began at 9 a.m. on the 19th, and "yesterday" ran from 9 a.m. on the 18th to 9 a.m. on the 19th. That day's high 107,499 USDT (PDH) and low 106,322.2 USDT (PDL) are drawn from the 9 a.m. candle on the 18th to the right edge.

• The 5 p.m. and 6 p.m. candles on the 19th wicked below the previous day's low (lowest 106,103.36 USDT). Yet both closed back above it (106,443.95 USDT and 107,401.47 USDT).
• The very next candle, 7 p.m., closed at 107,882.71 USDT — above the previous day's high — and price went on to 109,450.07 USDT at 3 a.m. on the 20th.

The previous week's lines (PWH 126,199.63 USDT, PWL 102,000 USDT) are drawn too, but they sit outside this view's price range.

An analogy

Think of the marks the tide leaves on a beach.

• Yesterday's highest tide leaves a line in the sand. If today's water passes it, you can say "it came further than yesterday". That is the previous day's high.
• Last week's highest mark is a rarer benchmark — harder to pass, and a bigger deal when it is. That is the previous week's high.
• One wave splashing past the line and pulling back is not the same as the water rising past it and staying. That is the difference between a wick and a close.

In practice

Three things that happen at the line

1. A wick pokes through and comes back — price fills the stop and breakout orders resting beyond the line, then returns. People call it a "sweep". The 5 p.m. and 6 p.m. candles on the 19th in the 1-hour chart above look like this.
2. A close goes through and price carries on — the line no longer holds and price heads for the next level. That is what followed the 7 p.m. close above the previous day's high.
3. Price stalls before reaching it — it runs out of steam just short of the line and turns. 5 September on the 4-hour chart below looks like this.

A 4-hour chart (25 August – 8 September 2025). The "now" of this example is 5 a.m. on 8 September, so this week began at 9 a.m. on 1 September, and last week's high 113,667.28 USDT (PWH, the 9 a.m. candle on 25 August) and low 107,350.1 USDT (PWL, the 9 a.m. candle on 30 August) are drawn from 25 August.

• On the first day of the week, the 1 p.m. candle on 1 September wicked below the previous week's low to 107,255 USDT, then closed at its own high (109,432.99 USDT). The green dashed line just under the previous week's low is the weak low (107,255 USDT) set at the tip of that wick.
• Price then rose to 113,384.62 USDT in the 9 p.m. candle on 5 September — 282.66 USDT below the previous week's high. That candle closed at 110,716.82 USDT.

Apart from that one wick on the first day, price stayed between last week's high and low all week. Last week's range acted as this week's fence. The two short lines on the right are the previous day's high (111,307.7 USDT) and low (109,977 USDT) — those of 6 September.

How traders use them

• As targets and boundaries — in an uptrend, the previous day/week high above is the next place price may reach, and the lows below are where you check whether the trend broke.
• Tell wicks from closes — first ask whether only a wick crossed the line or a close did. It is the same idea as the break rule in Part 2 (closes only).
• Together with structure — don't judge on a line alone. Look for other evidence lining up, such as an internal CHoCH the other way after a sweep.

Going deeper

Why orders gather at these lines

Just above yesterday's high sit the stop orders of short sellers and the "buy if it breaks" orders; just below yesterday's low sit the stops of buyers. For a big player such a spot is where a lot of volume can be bought or sold at once (liquidity). That is why price so often pokes past the line, fills those orders, and comes back. The liquidity built by equal highs and lows is the topic of Part 5, EQH · EQL.

Different cut-off, different line

Other chart services and exchanges may cut the day at another time (Korean midnight, the US market close, and so on). Then the same coin has a different previous-day high. When you compare with analysis from elsewhere, check which cut-off it uses first. Ours is 00:00 UTC (9 a.m. in Korea).

Which timeframe?

Previous-day levels are most useful on 15-minute and 1-hour charts, which look inside a day; previous-week levels on 1-hour and 4-hour charts, which look across days. On a daily chart "yesterday" is a single candle, so you simply read the previous candle's high and low — which is why our chart draws no previous-day lines on daily and longer timeframes.

On our chart

How to turn it on

Chart tab › SMC button › set Structure to "Swing" or "Swing + internal", then tick Previous day/week high·low under Add-ons. It is off at first. When Structure is "Off", the add-on ticks are greyed out and nothing is drawn (your ticks are kept).

Facts about our implementation

• A day is cut at 00:00 UTC (9 a.m. in Korea), a week at Monday 00:00 UTC (Monday 9 a.m. in Korea).
• Only the one day (week) right before the day (week) that contains "now" is drawn. When the day changes, it is recounted even if the candles are the same.
• Each line is a muted dashed line from the first candle of its day (week) to the right edge, with a PDH · PDL · PWH · PWL label at the right end (highs above the line, lows below). If that label would overlap an SMC label placed earlier (structure, equilibrium, EQH/EQL), it is hidden.
• Only the candles the chart has received (500 from Binance) count. If they do not cover the previous day (week) from start to end, that line is not drawn. For example, 500 one-minute candles cover just over 8 hours, so no previous-day line appears.
• On daily and weekly charts there is no previous-day line, only previous-week lines. On monthly charts there are neither.
• On a Binance chart, if a candle is missing inside the day (week) — a stretch not received because the connection dropped — the line is not drawn: no value rather than a wrong one. Upbit does not send candles with no trades, so its gaps are taken as they are.
• The candle still forming is left out.

Next, we read everything so far on one chart — Putting it together — reading all five on one chart.