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Marketable Securities (Tables) | 12 Months Ended
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Jun. 30, 2023
Marketable Securities |
Schedule of net gains and losses of marketable securities | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Year ended June 30,
​ |  | 2023 |  | 2022 |  | 2021
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Net gains recognized during the period on marketable securities | ​ | $ | 147 | ​ | $ | 81 | ​ | $ | —
Less: Net gains recognized during the period on marketable securities sold during the period | ​ |  | — | ​ |  | — | ​ |  | —
Unrealized gains (losses) recognized during the reporting period on marketable securities still held at the reporting date | ​ |  | (79) | ​ |  | (426) | ​ |  | (9)
​ | ​ | $ | 68 | ​ | $ | (345) | ​ | $ | (9)
Schedule of fair value of marketable securities | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | June 30, 2023 | ​ | June 30, 2022
​ | ​ | ​ | ​ | ​ | ​ | ​ | Unrealized | ​ | ​ | ​ | ​ | ​ | ​ | ​ | Unrealized
​ | Cost |  | Fair Value |  | Gain (Loss) |  | Cost |  | Fair Value |  | Gain (Loss)
Mutual Funds - Level 1 | $ | 5,651 | ​ | ​ | 5,136 | ​ | $ | (515) | ​ | $ | 5,504 | ​ | $ | 5,068 | ​ | $ | (436)

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