| Schedule of net interest income/(expense) | 
 Net interest income/expense includes: 
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 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
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 | 
 Year ended 
March 31, 2022 
 | 
 | 
 Year ended 
March 31, 2021  
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 | 
 Year ended 
March 31, 2020 
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 | 
(restated) | 
 | 
(restated) | 
 | 
(restated) | 
 
| Interest income: | 
 | 
 | 
 | 
 | 
 | 
 
| Interest income on financial assets recorded at amortized cost comprises: | 
 | 
 | 
 | 
 | 
 | 
 
| Interest income on securities repurchased under reverse repurchase agreements and amounts due from banks | 
$ | 
1,385  | 
 | 
 | 
$ | 
900  | 
 | 
 | 
$ | 
898  | 
 | 
 
| Interest income on margin loans | 
14,164  | 
 | 
 | 
3,163  | 
 | 
 | 
5,195  | 
 | 
 
| Interest income on loans to customers | 
4,612  | 
 | 
 | 
384  | 
 | 
 | 
328  | 
 | 
 
 | 
 | 
 | 
 | 
 | 
 | 
 
| Total interest income on financial assets recorded at amortized cost | 
20,161  | 
 | 
 | 
4,447  | 
 | 
 | 
6,421  | 
 | 
 
 | 
 | 
 | 
 | 
 | 
 | 
 
| Interest income on financial assets recorded in consolidated statements of operations and other comprehensive income | 
 | 
 | 
 | 
 | 
 | 
 
 | 
 | 
 | 
 | 
 | 
 | 
 
| Interest income on trading securities | 
69,992  | 
 | 
 | 
18,368  | 
 | 
 | 
7,160  | 
 | 
 
 | 
 | 
 | 
 | 
 | 
 | 
 
| Total interest income on financial assets recorded in consolidated statements of operations and other comprehensive income | 
69,992  | 
 | 
 | 
18,368  | 
 | 
 | 
7,160  | 
 | 
 
 | 
 | 
 | 
 | 
 | 
 | 
 
| Total interest income | 
$ | 
90,153  | 
 | 
 | 
$ | 
22,815  | 
 | 
 | 
$ | 
13,581  | 
 | 
 
| Interest expense: | 
 | 
 | 
 | 
 | 
 | 
 
| Interest expense on financial liabilities recorded at amortized cost comprises: | 
 | 
 | 
 | 
 | 
 | 
 
 | 
 | 
 | 
 | 
 | 
 | 
 
| Interest expense on securities repurchase agreement obligations | 
$ | 
46,731  | 
 | 
 | 
$ | 
10,497  | 
 | 
 | 
$ | 
7,074  | 
 | 
 
| Interest expense on customer accounts and deposits | 
16,336  | 
 | 
 | 
5,591  | 
 | 
 | 
755  | 
 | 
 
| Interest expense on debt securities issued | 
1,822  | 
 | 
 | 
2,363  | 
 | 
 | 
2,016  | 
 | 
 
| Interest expense on loans received | 
539  | 
 | 
 | 
133  | 
 | 
 | 
355  | 
 | 
 
| Other interest expense | 
21  | 
 | 
 | 
22  | 
 | 
 | 
—  | 
 | 
 
| Total interest expense on financial liabilities recorded at amortized cost | 
65,449  | 
 | 
 | 
18,606  | 
 | 
 | 
10,200  | 
 | 
 
 | 
 | 
 | 
 | 
 | 
 | 
 
| Total interest expense | 
$ | 
65,449  | 
 | 
 | 
$ | 
18,606  | 
 | 
 | 
$ | 
10,200  | 
 | 
 
  
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