SEC ownership of Ostin Technology Group Co., Ltd.

Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001803407.

CIK
0001803407
Symbol
OST on Nasdaq
Location
Nanjiang Jiangsu, China
Parsed ownership evidence
13D/G, 13F, and 3/4/5
Lead holder
Fong Shih-Song
13D/G signal
Fong Shih-Song
Latest evidence date
31 Mar 2026

Ownership snapshot

Top shareholders of Ostin Technology Group Co., Ltd. (13F + 13D/G + 3/4/5)

Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.

Lead holder
Fong Shih-Song
13D/G signal
Fong Shih-Song
Evidence rows
14
Latest as of
31 Mar 2026
13D/G 13F 3/4/5 Lead comparable stake: 4.5% 13D/G row: Fong Shih-Song Showing first 8 of 14 holder rows. Open remaining rows
Holder Evidence Ownership % Position 12M Net Δ As of
Fong Shih-Song
13D/G
4.5%
$21,021,788
4,832,595 shares
-$9,602,212 09 Jun 2025
Hon Devid
13D/G
4.3%
$19,964,112
4,589,451 shares
-$12,747,871 09 Jun 2025
Liao Yen-Kai
13D/G
3.6%
$21,659,040
3,888,517 shares
-$15,793,195 19 Jun 2025
Lo Sheng-Lun
13D/G
3.6%
$21,244,169
3,814,034 shares
-$17,968,631 19 Jun 2025
Hendri Jones
13D/G
3%
$14,162,660
3,255,784 shares
-$17,157,348 09 Jun 2025
Hsiao Tzu-Kai
13D/G
2.7%
$12,507,046
2,875,183 shares
-$17,420,945 09 Jun 2025
CITADEL ADVISORS LLC
13F
Company
13F
class O/S missing
$44,051
34,652 shares
31 Mar 2026
HRT FINANCIAL LP
13F
Company
13F
class O/S missing
$22,000
13,551 shares
31 Mar 2026
Show 6 additional holder rows in the full holder list
Holder Evidence Ownership % Position 12M Net Δ As of
Xiao Hong Yin
3/4/5
Director and Secretary, Director
class O/S missing
$6,510
3,850 shares
18 Mar 2026
UBS Group AG
13F
Company
13F
class O/S missing
$4,502
2,656 shares
31 Mar 2026
MORGAN STANLEY
13F
Company
13F
class O/S missing
$4,456
2,629 shares
31 Mar 2026
BARCLAYS PLC
13F
Company
13F
class O/S missing
$839
495 shares
31 Mar 2026
Federation Des Caisses Desjardins du Quebec
13F
Individual
13F
class O/S missing
$683
403 shares
31 Mar 2026
WELLS FARGO & COMPANY/MN
13F
Company
13F
class O/S missing
$271
160 shares
31 Mar 2026
How to read this table

Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.

Forms 3/4/5 flow

Insider trading overview

Insider buy and sell flow is broadly balanced over the last 12 months. No Buy or Sell transactions have been reported since 29 May 2025.

Buys
$0
Insiders: 0
Sells
$0
Insiders: 0
Net
$0
Shares: 0
Window
Last 12 months
4 rolling buckets
Buy value Sell value
Shares: 0 Shares: 0
Window (months) Buy shares Sell shares Buy $ Sell $ Net $
0-3 0 0 $0 $0 $0
3-6 0 0 $0 $0 $0
6-9 0 0 $0 $0 $0
9-12 0 0 $0 $0 $0

Reporting owners

Insider holders from Forms 3/4/5

Current reporting-owner rows connected to Ostin Technology Group Co., Ltd.. Open the relationship link for the CIK-to-CIK filing trail.

Rows
3
Lead holder
Xiao Hong Yin
Net 12M change
$0
Latest report
18 Mar 2026
Name Relationship Holdings Value Past Year Net Change Change % Valuation Report Date
Xiao Hong Yin Director and Secretary, Director $6,510 Mixed 18 Mar 2026
John Carl Mein Director Mixed 18 Mar 2026
Rongguo Cui Director Mixed 18 Mar 2026

Recent Insider Transactions by Companies or Individuals for Ostin Technology Group Co., Ltd.

Showing up to 300 most recent insider transactions from the last 12 months.

Insider Symbol Class Transaction % Reported value Reported price Shares Shares owned Date Ownership
Xiao Hong Yin OST Class A Ordinary Share 0 3,850 18 Mar 2026 Xiaohong Yin, sole owner/director of JQZY, holds voting power over its securities.
An asterisk next to the price means the reported price is likely invalid.
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