RIVN intraday timing of daily highs and lows (last ~3 years; 2023-06-30 to 2026-06-30)
RIVN’s intraday range is largely decided at the open. Across 751 trading days from 2023-06-30 to 2026-06-30, 41.5% of daily highs — and a comparable share of lows — first printed inside the opening 30 minutes, and at least one extreme occurred in that window on roughly 80% of sessions. That concentration makes the opening period the dominant range-setter for this sample.
We tested minute bars for the US regular session, recording the first-minute timestamp of each day’s high and low and grouping outcomes into 30‑minute buckets. The analysis below presents the full distribution, median times, and charts that show how the midday and power-hour hours contribute far less to extremes than the opening half-hour.
For RIVN over the past ~3 years, when in the session does the day's high or low actually get printed — do the extremes lock in during the opening 30 minutes, or does price keep carving fresh highs and lows into the closing bell? Thesis: a hugely outsized share of daily highs and lows are set in the first 30 minutes while the midday hours almost never mark either extreme, so RIVN defines its whole day's range at the open and mostly chops inside it, debunking the 'power hour sets the day' reflex.
How this was measured
Filtered RIVN minute bars to US regular session (Mon–Fri, 09:30–16:00 ET) over the trailing ~3 years ending at the latest available date. For each trading day, identified the minute of the FIRST occurrence of the daily high and the daily low. Bucketed those timestamps into 30-minute clock-time buckets (09:30–10:00, …, 15:30–16:00). Computed the share of days whose high/low printed in each bucket and in coarse windows: Opening 30 minutes (09:30–10:00), Midday (11:00–14:00), and Power hour (15:00–16:00). Also summarized median time-since-open for highs vs lows.
The key numbers
Reading the numbers
RIVN prints the day's high in the opening 30 minutes on about 41.54% of days and the low there on about 42.61%; on roughly 80.03% of days either the high or low occurs in that first half-hour, so the open is disproportionately decisive.
The charts
The big thing to look at is the towering 09:30 bar: 41.54% of highs and 42.61% of lows occur in the opening 30 minutes, far larger than any single later 30‑minute bucket. Most midday buckets sit in the low single digits to mid‑single digits; the late 15:30 bucket rises (highs 10.25%, lows 12.65%) but still remains much smaller than the open. In plain terms, the chart shows the day’s extremes are overwhelmingly set at the open, and the stock mostly trades inside that range through the middle of the session.
Group the day coarsely and the opening 09:30–10:00 window stands out: 41.54% of highs and 42.61% of lows happen there, versus 23.30%/21.17% in midday and 15.98%/18.64% in the power hour. The "Other" bucket covers the remainder (about 19.17% of highs, 17.58% of lows). That reinforces the thesis: the open is the single most important window for setting the day’s high or low, while the power hour contributes noticeably less.
The timing distribution is skewed toward the early session: median times in the headline stats are 3,180 seconds (53 minutes) for the first daily high and 3,000 seconds (50 minutes) for the first daily low, so half the extremes appear within the first hour. The box‑plot summaries show means of 123.39 minutes (highs) and 127.05 minutes (lows), with a min of 0 and a max of 389 minutes, meaning rare late‑day extremes pull the average later while the typical day’s extreme is much earlier. Bottom line: the central tendency is early (around the first hour), but there’s a long right tail of occasional late highs/lows.
30-minute bucket summary (counts and shares out of all days)
| bucket_start_et | high_count | high_share | low_count | low_share |
|---|---|---|---|---|
| 09:30 | 312 | 0.4154 | 320 | 0.4261 |
| 10:00 | 73 | 0.0972 | 72 | 0.0959 |
| 10:30 | 41 | 0.0546 | 42 | 0.0559 |
| 11:00 | 41 | 0.0546 | 26 | 0.0346 |
| 11:30 | 31 | 0.0413 | 28 | 0.0373 |
| 12:00 | 27 | 0.036 | 21 | 0.028 |
| 12:30 | 19 | 0.0253 | 23 | 0.0306 |
| 13:00 | 18 | 0.024 | 21 | 0.028 |
| 13:30 | 19 | 0.0253 | 19 | 0.0253 |
| 14:00 | 20 | 0.0266 | 21 | 0.028 |
| 14:30 | 30 | 0.0399 | 18 | 0.024 |
| 15:00 | 43 | 0.0573 | 45 | 0.0599 |
| 15:30 | 77 | 0.1025 | 95 | 0.1265 |
The takeaway
Short answer: yes — RIVN usually pins a large part of the day's range at the open rather than carving fresh highs/lows into the close. In 751 trading days, 41.5% of daily highs and 42.6% of daily lows first printed in the opening 30 minutes, and at least one extreme occurred in that window on 80.0% of sessions. Far fewer extremes occur later in the day—the final hour and the midday window each take much smaller shares of daily highs/lows. This is a strong, practical signal: with 751 days and an 80% incidence, the early-session dominance is robust for the period measured. It isn’t absolute—you will still see intraday extensions on some days—but the pattern is a clear leaning, not a coin flip. Practical takeaway: prioritize the opening 30 minutes for range-setting on RIVN; don’t assume the power hour typically defines the day.
The fine print
- Buckets are 30-minute coarse slices; a 1–5 minute breakdown could shift marginal shares between adjacent buckets.
- When multiple bars hit the same extreme price we record the first occurrence; later retests are excluded.
- Early-close half-days shorten the session and mechanically reduce the chance late buckets capture extremes.