<<This is analyzed by ChatGPT, so it may not be accurate, so please take it lightly!>>
To reference the stock price direction of Hynix and Samsung Electronics, I referred a lot to Micron and SanDisk in the US market the previous day, and analyzed to what extent they actually have an impact.
o Period: June 9, 2026 ~ September 9, 2026 overall (63 trading days)
o US Market: MU (Micron), SNDK (SanDisk) regular market closing price changes
o Korean Market: SK Hynix and Samsung Electronics price changes on the next nearest Korean trading day after the corresponding US trading day ends
First, the conclusion is,
As the volatility of MU/SNDK increases, the direction of Hynix/Samsung Electronics stock prices matches.
In particular, when SNDK moves ±5% or more, the direction of Hynix stock price the next day matched 81.1%.
Please refer to the details below.
o Match Rate
US Stock → Korean Stock | Days of Direction Match | Total Trading Days | Match Rate |
|---|
MU → SK Hynix | 43 | 63 | 68.25% |
MU → Samsung Electronics | 41 | 63 | 65.08% |
SNDK → SK Hynix | 45 | 63 | 71.43% |
SNDK → Samsung Electronics | 43 | 63 | 68.25% |
Over the past 3 months, SNDK better explained the direction of Korean memory stocks than MU.
SNDK → SK Hynix: 71.43%
SNDK → Samsung Electronics: 68.25%
MU → SK Hynix: 68.25%
MU → Samsung Electronics: 65.08%
In particular, from the perspective of "Can we judge Hynix the next day by looking at how US memory stocks moved overnight?" that the user is interested in, the result shows that out of the last 63 observations, the direction of SNDK matched Hynix by approximately 71.4%.
And this time, we filtered to see whether SK Hynix moved in the same direction on the next Korean trading day when the movement of US memory stocks was above a certain level.
1. MU → Next Day SK Hynix
MU Previous Day Change Condition | Number of Trading Days | Same Direction | Match Rate |
|---|
±1% or more | 49 | 34 | 69.39% |
±2% or more | 39 | 29 | 74.36% |
±5% or more | 22 | 17 | 77.27% |
2. SNDK → SK Hynix the Next Day
SNDK Previous Day Change Condition | Number of Trading Days | Same Direction | Match Rate |
|---|
±1% or more | 52 | 40 | 76.92% |
±2% or more | 47 | 37 | 78.72% |
±5% or more | 37 | 30 | 81.08% |
At a Glance
Match Rate of SK Hynix Direction the Next Day Based on US Memory Stock Price Fluctuations
Analysis from June 9th to September 9th, 2026. The ratio of SK Hynix's direction matching with the Korean trading day following a change in US stock prices.
MU → Hynix
SNDK → Hynix
68%72%76%80%84%±1%±2%±5%
MU
The match rate with SK Hynix's direction increased as the price fluctuation became larger.
±1% or more → 69.4%
±2% or more → 74.4%
±5% or more → 77.3%
SNDK
A stronger relationship was observed.
±1% or more → 76.9%
±2% or more → 78.7%
±5% or more → 81.1%
In other words, the data from the past 3 months shows
if SNDK rises/falls by 5% or more, the probability that Hynix will also rise/fall the next day is about 81%
This is the result.
SNDK explained the direction of Hynix better than MU the next day.
US Stock | ±1% | ±2% | ±5% |
|---|
MU → Hynix | 69.4% | 74.4% | 77.3% |
SNDK → Hynix | 76.9% | 78.7% | 81.1% |
The most important part from an investment perspective
Rather than simply "US memory stock prices rose/fell", it seems that how much they moved is much more important.
Especially in this 3-month table,
SNDK ±5% or more → Hynix direction match 81.1%
a fairly high figure appeared.
